Method of retaining a substrate during a substrate transferring process

ABSTRACT

A method and apparatus for processing substrates using a multi-chamber processing system, or cluster tool, that has an increased system throughput, increased system reliability, improved device yield performance, a more repeatable wafer processing history (or wafer history), and a reduced footprint. The various embodiments of the cluster tool may utilize two or more robots that are configured in a parallel processing configuration to transfer substrates between the various processing chambers retained in the processing racks so that a desired processing sequence can be performed on the substrates. In one aspect, the parallel processing configuration contains two or more robot assemblies that are adapted to move in a vertical and horizontal directions, to access the various processing chambers retained in generally adjacently positioned processing racks. Generally, the various embodiments described herein are advantageous since each row or group of substrate processing chambers are serviced by two or more robots to allow for increased throughput and increased system reliability. Also, the various embodiments described herein are generally configured to minimize and control the particles generated by the substrate transferring mechanisms, to prevent device yield and substrate scrap problems that can affect the cost of ownership of the cluster tool. The flexible and modular architecture allows the user to configure the number of processing chambers, processing racks, and processing robots required to meet the throughput needs of the user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/315,873, filed Dec. 22, 2005, which is herein incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention generally relate to an integratedprocessing system containing multiple processing stations and robotsthat are capable of processing multiple substrates in parallel.

2. Description of the Related Art

The process of forming electronic devices is commonly done in amulti-chamber processing system (e.g., a cluster tool) that has thecapability to sequentially process substrates, (e.g., semiconductorwafers) in a controlled processing environment. Typical cluster toolsused to deposit (i.e., coat) and develop a photoresist material,commonly known as a track lithography tool, or used to performsemiconductor cleaning processes, commonly described as a wet/cleantool, will include a mainframe that houses at least one substratetransfer robot which transports substrates between a pod/cassettemounting device and multiple processing chambers that are connected tothe mainframe. Cluster tools are often used so that substrates can beprocessed in a repeatable way in a controlled processing environment. Acontrolled processing environment has many benefits which includeminimizing contamination of the substrate surfaces during transfer andduring completion of the various substrate processing steps. Processingin a controlled environment thus reduces the number of generated defectsand improves device yield.

The effectiveness of a substrate fabrication process is often measuredby two related and important factors, which are device yield and thecost of ownership (CoO). These factors are important since they directlyaffect the cost to produce an electronic device and thus a devicemanufacturer's competitiveness in the market place. The CoO, whileaffected by a number of factors, is greatly affected by the system andchamber throughput, or simply the number of substrates per hourprocessed using a desired processing sequence. A process sequence isgenerally defined as the sequence of device fabrication steps, orprocess recipe steps, completed in one or more processing chambers inthe cluster tool. A process sequence may generally contain varioussubstrate (or wafer) electronic device fabrication processing steps. Inan effort to reduce CoO, electronic device manufacturers often spend alarge amount of time trying to optimize the process sequence and chamberprocessing time to achieve the greatest substrate throughput possiblegiven the cluster tool architecture limitations and the chamberprocessing times. In track lithography type cluster tools, since thechamber processing times tend to be rather short, (e.g., about a minuteto complete the process) and the number of processing steps required tocomplete a typical process sequence is large, a significant portion ofthe time it takes to complete the processing sequence is taken uptransferring the substrates between the various processing chambers. Atypical track lithography process sequence will generally include thefollowing steps: depositing one or more uniform photoresist (or resist)layers on the surface of a substrate, then transferring the substrateout of the cluster tool to a separate stepper or scanner tool to patternthe substrate surface by exposing the photoresist layer to a photoresistmodifying electromagnetic radiation, and then developing the patternedphotoresist layer. If the substrate throughput in a cluster tool is notrobot limited, the longest process recipe step will generally limit thethroughput of the processing sequence. This is usually not the case intrack lithography process sequences, due to the short processing timesand large number of processing steps. Typical system throughput for theconventional fabrication processes, such as a track lithography toolrunning a typical process, will generally be between 100-120 substratesper hour.

Other important factors in the CoO calculation are the systemreliability and system uptime. These factors are very important to acluster tool's profitability and/or usefulness, since the longer thesystem is unable to process substrates the more money is lost by theuser due to the lost opportunity to process substrates in the clustertool. Therefore, cluster tool users and manufacturers spend a largeamount of time trying to develop reliable processes, reliable hardwareand reliable systems that have increased uptime.

The push in the industry to shrink the size of semiconductor devices toimprove device processing speed and reduce the generation of heat by thedevice, has reduced the industry's tolerance for process variability. Tominimize process variability an important factor in the tracklithography processing sequences is the issue of assuring that everysubstrate run through a cluster tool has the same “wafer history.” Asubstrate's wafer history is generally monitored and controlled byprocess engineers to assure that all of the device fabricationprocessing variables that may later affect a device's performance arecontrolled, so that all substrates in the same batch are alwaysprocessed the same way. To assure that each substrate has the same“wafer history” requires that each substrate experiences the samerepeatable substrate processing steps (e.g., consistent coating process,consistent hard bake process, consistent chill process, etc.) and thetiming between the various processing steps is the same for eachsubstrate. Lithography type device fabrication processes can beespecially sensitive to variations in process recipe variables and thetiming between the recipe steps, which directly affects processvariability and ultimately device performance. Therefore, a cluster tooland supporting apparatus capable of performing a process sequence thatminimizes process variability and the variability in the timing betweenprocess steps is needed. Also, a cluster tool and supporting apparatusthat is capable of performing a device fabrication process that deliversa uniform and repeatable process result, while achieving a desiredsubstrate throughput is also needed.

Therefore, there is a need for a system, a method and an apparatus thatcan process a substrate so that it can meet the required deviceperformance goals and increase the system throughput and thus reduce theprocess sequence CoO.

SUMMARY OF THE INVENTION

The present invention generally provide a method of transferring asubstrate, comprising positioning a substrate on a substrate supportingdevice between a substrate contact member and a reaction member that arepositioned on the substrate supporting device, generating a substrateholding force by use of an actuator that urges the substrate contactmember against the substrate and the substrate against the reactionmember, and generating a restraining force that is adapted torestraining the movement of the substrate contact member during theprocess of transferring a substrate by use of a brake assembly.

Embodiments of the invention further provide a method of transferring asubstrate, comprising positioning a substrate on a substrate supportingdevice between a substrate contact member and a reaction member that arepositioned on the substrate reporting device, coupling an actuatorhaving a connection member to the substrate contact member so that theconnection member couples the actuator to the substrate contact member,applying a holding force to the substrate using an actuator that urgesthe substrate contact member against the substrate and the substrateagainst the reaction member, storing energy in a compliant member thatis positioned between the substrate contact member and the connectionmember, restraining the movement of the connection member after theholding force has been applied to minimize the amount of variation inthe holding force during the process of transferring the substrate, andsensing the movement of the substrate by sensing the movement of thesubstrate contact surface due to the reduction in the stored energy inthe compliant member.

Embodiments of the invention further provide a method of transferring asubstrate, comprising receiving a substrate positioned within a firstprocess chamber onto a robot substrate support, wherein the step ofreceiving the substrate comprises positioning a substrate on the robotsubstrate support between a substrate contact member and a reactionmember that are positioned on the robot substrate support, generating asubstrate holding force by use of an actuator that urges the substratecontact member against the substrate and the substrate against thereaction member, and positioning a brake assembly to generate arestraining force that restrains the movement of the substrate contactmember during the process of transferring a substrate, and transferringthe substrate and the robot substrate support from a position within thefirst process chamber to a position within a second process chamberwhich is positioned a distance from the first process chamber along afirst direction using a first robot assembly which is adapted toposition the substrate at a desired position in the first direction andat a desired position in a second direction, wherein the seconddirection is generally orthogonal to the first direction.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A is an isometric view illustrating one embodiment of a clustertool of the invention;

FIG. 1B is a plan view of the processing system illustrated in FIG. 1A,according to the present invention;

FIG. 1C is a side view that illustrates one embodiment of the firstprocessing rack 60 according to the present invention;

FIG. 1D is a side view that illustrates one embodiment of the secondprocessing rack 80 according to the present invention;

FIG. 1E is a plan view of the processing system illustrated in FIG. 1B,according to the present invention;

FIG. 1F illustrates one embodiment of a process sequence containingvarious process recipe steps that may be used in conjunction with thevarious embodiments of the cluster tool described herein;

FIG. 1G is a plan view of a processing system illustrated in FIG. 1Bthat illustrates a transfer path of a substrate through the cluster toolfollowing the process sequence illustrated in FIG. 1F;

FIG. 2A is a plan view of a processing system, according to the presentinvention;

FIG. 2B is a plan view of a processing system illustrated in FIG. 2A,according to the present invention;

FIG. 2C is a plan view of a processing system illustrated in FIG. 2Bthat illustrates a transfer path of a substrate through the cluster toolfollowing the process sequence illustrated in FIG. 1F;

FIG. 3A is a plan view of a processing system, according to the presentinvention;

FIG. 3B is a plan view of a processing system illustrated in FIG. 3Athat illustrates a transfer path of a substrate through the cluster toolfollowing the process sequence illustrated in FIG. 1F;

FIG. 4A is a plan view of a processing system, according to the presentinvention;

FIG. 4B is a plan view of a processing system illustrated in FIG. 4Athat illustrates a transfer path of a substrate through the cluster toolfollowing the process sequence illustrated in FIG. 1F;

FIG. 5A is a plan view of a processing system, according to the presentinvention;

FIG. 5B is a plan view of a processing system illustrated in FIG. 5Athat illustrates a transfer path of a substrate through the cluster toolfollowing the process sequence illustrated in FIG. 1F;

FIG. 6A is a plan view of a processing system, according to the presentinvention;

FIG. 6B is a plan view of a processing system illustrated in FIG. 6Athat illustrates two possible transfer paths of a substrate through thecluster tool following the process sequence illustrated in FIG. 1F;

FIG. 6C is a plan view of a processing system, according to the presentinvention;

FIG. 6D is a plan view of a processing system illustrated in FIG. 6Cthat illustrates two possible transfer paths of a substrate through thecluster tool following the process sequence illustrated in FIG. 1F;

FIG. 7A is a side view of one embodiment of an exchange chamber,according to the present invention;

FIG. 7B is a plan view of the processing system illustrated in FIG. 1B,according to the present invention;

FIG. 8A is an isometric view illustrating another embodiment of acluster tool illustrated in FIG. 1A that has an environmental enclosureattached, according to the present invention;

FIG. 8B is a cross-sectional view of the cluster tool illustrated inFIG. 8A, according to the present invention;

FIG. 8C is a cross-sectional view of one configuration of the accordingto the present invention;

FIG. 9A is an isometric view illustrating one embodiment of a robot thatmay be adapted to transfer substrates in various embodiments of thecluster tool;

FIG. 10A is an isometric view illustrating one embodiment of a robothardware assembly having a single robot assembly according to thepresent invention;

FIG. 10B is an isometric view illustrating one embodiment of a robothardware assembly having a dual robot assembly according to the presentinvention;

FIG. 10C is a cross-sectional view of one embodiment of the robothardware assembly illustrated in FIG. 10A, according to the presentinvention;

FIG. 10D is a cross-sectional view of one embodiment of a robot hardwareassembly, according to the present invention;

FIG. 10E is a cross-sectional view of one embodiment of the robothardware assembly illustrated in FIG. 10A, according to the presentinvention;

FIG. 11A is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11B illustrates various possible paths of the center of thesubstrate as it is transferred into a processing chamber, according tothe present invention;.

FIG. 11C is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11D is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11E is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11F is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11G is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11H is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11I is a plan view of one embodiment of robot assembly illustratingvarious positions of the robot blade as it transfers a substrate into aprocessing chamber, according to the present invention;

FIG. 11J is a plan view of one embodiment of robot assembly according tothe present invention;

FIG. 11K is a plan view of a conventional SCARA robot of robot assemblypositioned near a processing rack;

FIG. 12A is a cross-sectional view of the horizontal motion assemblyillustrated in FIG. 9A, according to the present invention;

FIG. 12B is a cross-sectional view of the horizontal motion assemblyillustrated in FIG. 9A, according to the present invention;

FIG. 12C is a cross-sectional view of the horizontal motion assemblyillustrated in FIG. 9A, according to the present invention;

FIG. 13A is a cross-sectional view of the vertical motion assemblyillustrated in FIG. 9A, according to the present invention;

FIG. 13B is an isometric view illustrating one embodiment of a robotillustrated in FIG. 13A that may be adapted to transfer substrates invarious embodiments of the cluster tool;

FIG. 14A is an isometric view illustrating one embodiment of a robotthat may be adapted to transfer substrates in various embodiments of thecluster tool;

FIG. 15A is an isometric view illustrating one embodiment of a robotthat may be adapted to transfer substrates in various embodiments of thecluster tool;

FIG. 16A is a plan view illustrating one embodiment of a robot bladeassembly that may be adapted to transfer substrates in variousembodiments of the cluster tool;

FIG. 16B is an side cross-section view illustrating one embodiment ofthe robot blade assembly shown in FIG. 16A that may be adapted totransfer substrates in various embodiments of the cluster tool;

FIG. 16C is a plan view illustrating one embodiment of a robot bladeassembly that may be adapted to transfer substrates in variousembodiments of the cluster tool;

FIG. 16D is a plan view illustrating one embodiment of a robot bladeassembly that may be adapted to transfer substrates in variousembodiments of the cluster tool.

DETAILED DESCRIPTION

The present invention generally provides an apparatus and method forprocessing substrates using a multi-chamber processing system (e.g., acluster tool) that has an increased system throughput, increased systemreliability, improved device yield performance, a more repeatable waferprocessing history (or wafer history), and a reduced footprint. In oneembodiment, the cluster tool is adapted to perform a track lithographyprocess in which a substrate is coated with a photosensitive material,is then transferred to a stepper/scanner, which exposes thephotosensitive material to some form of radiation to form a pattern inthe photosensitive material, and then certain portions of thephotosensitive material are removed in a developing process completed inthe cluster tool. In another embodiment, the cluster tool is adapted toperform a wet/clean process sequence in which various substrate cleaningprocesses are performed on a substrate in the cluster tool.

FIGS. 1-6 illustrate some of the various robot and process chamberconfigurations that may be used in conjunction with various embodimentsof this invention. The various embodiments of the cluster tool 10generally utilize two or more robots that are configured in a parallelprocessing configuration to transfer substrates between the variousprocessing chambers retained in the processing racks (e.g., elements 60,80, etc.) so that a desired processing sequence can be performed on thesubstrates. In one embodiment, the parallel processing configurationcontains two or more robot assemblies 11 (elements 11A, 11B and 11C inFIGS. 1A and 1B) that are adapted to move a substrate in a vertical(hereafter the z-direction) and horizontal directions, i.e., transferdirection (x-direction) and a direction orthogonal to the transferdirection (y-direction), so that the substrates can be processed invarious processing chambers retained in the processing racks (e.g.,elements 60 and 80) which are aligned along the transfer direction. Oneadvantage of the parallel processing configuration is that if one of therobots becomes inoperable, or is taken down for servicing, the systemcan still continue to process substrates using the other robots retainedin the system. Generally, the various embodiments described herein areadvantageous since each row or group of substrate processing chambersare serviced by two or more robots to allow for increased throughput andincreased system reliability. Also, the various embodiments describedherein are generally configured to minimize and control the particlesgenerated by the substrate transferring mechanisms, to prevent deviceyield and substrate scrap problems that can affect the CoO of thecluster tool. Another advantage of this configuration is the flexibleand modular architecture allows the user to configure the number ofprocessing chambers, processing racks, and processing robots required tomeet the throughput needs of the user. While FIGS. 1-6 illustrate oneembodiment of a robot assembly 11 that can be used to carryout variousaspects of the invention, other types of robot assemblies 11 may beadapted to perform the same substrate transferring and positioningfunction(s) without varying from the basic scope of the invention.

First Cluster Tool Configuration

A. System Configuration

FIG. 1A is an isometric view of one embodiment of a cluster tool 10 thatillustrates a number of the aspects of the present invention that may beused to advantage. FIG. 1A illustrates an embodiment of the cluster tool10 which contains three robots that are adapted to access the variousprocess chambers that are stacked vertically in a first processing rack60 and a second processing rack 80 and an external module 5. In oneaspect, when the cluster tool 10 is used to complete a photolithographyprocessing sequence the external module 5, may be a stepper/scannertool, that is attached to the rear region 45 (not shown in FIG. 1A) toperform some additional exposure type processing step(s). One embodimentof the cluster tool 10, as illustrated in FIG. 1A, contains a front endmodule 24 and a central module 25.

FIG. 1B is a plan view of the embodiment of the cluster tool 10 shown inFIG. 1A. The front end module 24 generally contains one or more podassemblies 105 (e.g., items 105A-D) and a front end robot assembly 15(FIG. 1B). The one or more pod assemblies 105, or front-end openingunified pods (FOUPs), are generally adapted to accept one or morecassettes 106 that may contain one or more substrates “W”, or wafers,that are to be processed in the cluster tool 10. In one aspect, thefront end module 24 also contains one or more pass-through positions 9(e.g., elements 9A-C FIG. 1B).

In one aspect, the central module 25 has a first robot assembly 11A, asecond robot assembly 11B, a third robot assembly 11C, a rear robotassembly 40, a first processing rack 60 and a second processing rack 80.The first processing rack 60 and a second processing rack 80 containvarious processing chambers (e.g., coater/developer chamber, bakechamber, chill chamber, wet clean chambers, etc. which are discussedbelow (FIGS. 1C-D)) that are adapted to perform the various processingsteps found in a substrate processing sequence.

FIGS. 1C and 1D illustrate side views of one embodiment of the firstprocessing rack 60 and second processing rack 80 as viewed when facingthe first processing rack 60 and second processing racks 80 whilestanding on the side closest to side 60A, and thus will coincide withthe views shown in FIGS. 1-6. The first processing rack 60 and secondprocessing rack 80 generally contain one or more groups of verticallystacked processing chambers that are adapted to perform some desiredsemiconductor or flat panel display device fabrication processing stepson a substrate. For example, in FIG. 1C the first process rack 60 hasfive groups, or columns, of vertically stacked processing chambers. Ingeneral these device fabrication processing steps may include depositinga material on a surface of the substrate, cleaning a surface of thesubstrate, etching a surface of the substrate, or exposing the substrateto some form of radiation to cause a physical or chemical change to oneor more regions on the substrate. In one embodiment, the firstprocessing rack 60 and second processing rack 80 have one or moreprocessing chambers contained in them that can be adapted to perform oneor more photolithography processing sequence steps. In one aspect,processing racks 60 and 80 may contain one or more coater/developerchambers 160, one or more chill chambers 180, one or more bake chambers190, one or more optical edge bead removal (OEBR) chambers 162, one ormore post exposure bake (PEB) chambers 130, one or more support chambers165, an integrated bake/chill chamber 800, and/or one or morehexamethyldisilazane (HMDS) processing chambers 170. Exemplarycoater/developer chambers, chill chambers, bake chambers, OEBR chambers,PEB chambers, support chambers, integrated bake/chill chambers and/orHMDS processing chambers that may be adapted to benefit one or moreaspects of the invention are further described in the commonly assignedU.S. patent application Ser. No. 11/112,281, filed Apr. 22, 2005, whichis hereby incorporated by reference in its entirety to the extent notinconsistent with the claimed invention. Examples of an integratedbake/chill chamber that may be adapted to benefit one or more aspects ofthe invention are further described in the commonly assigned U.S. patentapplication Ser. No. 11/111,154, filed Apr. 11, 2005 and U.S. patentapplication Ser. No. 11/111,353, filed Apr. 11, 2005, which are herebyincorporated by reference in its entirety to the extent not inconsistentwith the claimed invention. Examples of a processing chambers and orsystems that may be adapted to perform one or more cleaning processes ona substrate and may be adapted to benefit one or more aspects of theinvention is further described in the commonly assigned U.S. patentapplication Ser. No. 09/891,849, filed Jun. 25, 2001 and U.S. patentapplication Ser. No. 09/945,454, filed Aug. 31, 2001 and, which arehereby incorporated by reference in its entirety to the extent notinconsistent with the claimed invention.

In one embodiment, as shown in FIG. 1C, where the cluster tool 10 isadapted to perform a photolithography type process, the first processingrack 60 may have eight coater/developer chambers 160 (labeled CD1-8),eighteen chill chambers 180 (labeled C1-18), eight bake chambers 190(labeled B1-8), six PEB chambers 130 (labeled PEB1-6), two OEBR chambers162 (labeled 162) and/or six HMDS process chambers 170 (labeled DP1-6).In one embodiment, as shown in FIG. 1D, where the cluster tool 10 isadapted to perform a photolithography type process, the second processrack 80 may have eight coater/developer chambers 160 (labeled CD1-8),six integrated bake/chill chambers 800 (labeled BC1-6), six HMDS processchambers 170 (labeled DP1-6) and/or six support chambers 165 (labeledS1-6). The orientation, positioning, type and number of process chambersshown in the FIGS. 1C-D are not intended to be limiting as to the scopeof the invention, but are intended to illustrate an embodiment of theinvention.

Referring to FIG. 1B, in one embodiment, the front end robot assembly 15is adapted to transfer substrates between a cassette 106 mounted in apod assembly 105 (see elements 105A-D) and the one or more of thepass-through positions 9 (see pass-through positions 9A-C in FIG. 1B).In another embodiment, the front end robot assembly 15 is adapted totransfer substrates between a cassette mounted in a pod assembly 105 andthe one or more processing chambers in the first processing racks 60 ora second processing rack 80 that abuts the front end module 24. Thefront end robot assembly 15 generally contains a horizontal motionassembly 15A and a robot 15B, which in combination are able to positiona substrate in a desired horizontal and/or vertical position in thefront end module 24 or the adjoining positions in the central module 25.The front end robot assembly 15 is adapted to transfer one or moresubstrates using one or more robot blades 15C, by use commands sent froma system controller 101 (discussed below). In one sequence the front endrobot assembly 15 is adapted to transfer a substrate from the cassette106 to one of the pass-through positions 9 (e.g., elements 9A-C in FIG.1B). Generally, a pass-through position is a substrate staging area thatmay contain a pass-through processing chamber that has features similarto an exchange chamber 533 (FIG. 7A), or a conventional substratecassette 106, and is able to accept a substrate from a first robot sothat it can be removed and repositioned by a second robot. In oneaspect, the pass-through processing chamber mounted in a pass-throughposition may be adapted to perform one or more processing steps in adesired processing sequence, for example, a HMDS process step or achill/cooldown processing step or substrate notch align. In one aspect,each of the pass-through positions (elements 9A-C in FIG. 1B) may beaccessed by each of the central robot assemblies (i.e., first robotassembly 11A, second robot assembly 11B, and third robot assembly 11C).

Referring to FIGS. 1A-B, the first robot assembly 11A, the second robotassembly 11B, and the third robot assembly 11C are adapted to transfersubstrates to the various processing chambers contained in the firstprocessing rack 60 and the second processing rack 80. In one embodiment,to perform the process of transferring substrates in the cluster tool 10the first robot assembly 11A, the second robot assembly 11B, and thethird robot assembly 11C have similarly configured robot assemblies 11which each have at least one horizontal motion assembly 90, a verticalmotion assembly 95, and a robot hardware assembly 85 which are incommunication with a system controller 101. In one aspect, the side 60Bof the first processing rack 60, and the side 80A of the secondprocessing rack 80 are both aligned along a direction parallel to thehorizontal motion assembly 90 (described below) of each of the variousrobot assemblies (i.e., first robot assembly 11A, second robot assembly11B, third robot assembly 11C).

The system controller 101 is adapted to control the position and motionof the various components used to complete the transferring process. Thesystem controller 101 is generally designed to facilitate the controland automation of the overall system and typically includes a centralprocessing unit (CPU) (not shown), memory (not shown), and supportcircuits (or I/O) (not shown). The CPU may be one of any form ofcomputer processors that are used in industrial settings for controllingvarious system functions, chamber processes and support hardware (e.g.,detectors, robots, motors, gas sources hardware, etc.) and monitor thesystem and chamber processes (e.g., chamber temperature, processsequence throughput, chamber process time, I/O signals, etc.). Thememory is connected to the CPU, and may be one or more of a readilyavailable memory, such as random access memory (RAM), read only memory(ROM), floppy disk, hard disk, or any other form of digital storage,local or remote. Software instructions and data can be coded and storedwithin the memory for instructing the CPU. The support circuits are alsoconnected to the CPU for supporting the processor in a conventionalmanner. The support circuits may include cache, power supplies, clockcircuits, input/output circuitry, subsystems, and the like. A program(or computer instructions) readable by the system controller 101determines which tasks are performable on a substrate. Preferably, theprogram is software readable by the system controller 101, that includescode to perform tasks relating to monitoring and execution of theprocessing sequence tasks and various chamber process recipe steps.

Referring to FIG. 1B, in one aspect of the invention the first robotassembly 11A is adapted to access and transfer substrates between theprocessing chambers in the first processing rack 60 from at least oneside, e.g., the side 60B. In one aspect, the third robot assembly 11C isadapted to access and transfer substrates between the processingchambers in the second processing rack 80 from at least one side, e.g.,the side 80A. In one aspect, the second robot assembly 11B is adapted toaccess and transfer substrates between the processing chambers in thefirst processing rack 60 from side 60B and the second processing rack 80from side 80A. FIG. 1E illustrates a plan view of the embodiment of thecluster tool 10 shown in FIG. 1B, in which a robot blade 87 from thesecond robot assembly 11B has been extended into a processing chamber inthe first processing rack 60 through side 60B. The ability to extend therobot blade 87 into a processing chamber and retract the robot blade 87from the processing chamber is generally completed by cooperativemovement of the components contained in the horizontal motion assembly90, vertical motion assembly 95, and robot hardware assembly 85, and byuse of commands sent from the system controller 101. The ability of twoor more robots to “overlap” with one another, such as the first robotassembly 11A and the second robot assembly 11B or the second robotassembly 11B and the third robot assembly 11C, is advantageous since itallows substrate transfer redundancy which can improve the clusterreliability, uptime, and also increase the substrate throughput. Robot“overlap” is generally the ability of two or more robots to accessand/or independently transfer substrates between the same processingchambers in the processing rack. The ability of two or more robots toredundantly access processing chambers can be an important aspect inpreventing system robot transfer bottlenecks, since it allows an underutilized robot to help out a robot that is limiting the systemthroughput. Therefore, the substrate throughput can be increased, asubstrate's wafer history can be made more repeatable, and the systemreliability can be improved through the act of balancing the load thateach robot takes during the processing sequence.

In one aspect of the invention, the various overlapping robot assemblies(e.g., elements 11A, 11B, 11C, 11D, 11E, etc. in FIGS. 1-6) are able tosimultaneously access processing chambers that are horizontally adjacent(x-direction) or vertically adjacent (z-direction) to each other. Forexample, when using the cluster tool configurations illustrated in FIGS.1B and 1C, the first robot assembly 11A is able to access processingchamber CD6 in the first processing rack 60 and the second robotassembly 11B is able to access processing chamber CD5 simultaneouslywithout colliding or interfering with each other. In another example,when using the cluster tool configurations illustrated in FIGS. 1B and1D, the third robot assembly 11C is able to access processing chamber C6in the second processing rack 80 and the second robot assembly 11B isable to access processing chamber P6 simultaneously without colliding orinterfering with each other.

In one aspect, the system controller 101 is adapted to adjust thesubstrate transfer sequence through the cluster tool based on acalculated optimized throughput or to work around processing chambersthat have become inoperable. The feature of the system controller 101which allows it to optimize throughput is known as the logicalscheduler. The logical scheduler prioritizes tasks and substratemovements based on inputs from the user and various sensors distributedthroughout the cluster tool. The logical scheduler may be adapted toreview the list of future tasks requested of each of the various robots(e.g., front end robot assembly 15, first robot assembly 11A, secondrobot assembly 11B, third robot assembly 11C, etc.), which are retainedin the memory of the system controller 101, to help balance the loadplaced on each of the various robots. The use of a system controller 101to maximize the utilization of the cluster tool will improve the clustertool's CoO, makes the wafer history more repeatable, and can improve thecluster tool's reliability.

In one aspect, the system controller 101 is also adapted to preventcollisions between the various overlapping robots and optimize thesubstrate throughput. In one aspect, the system controller 101 isfurther programmed to monitor and control the motion of the horizontalmotion assembly 90, a vertical motion assembly 95, and a robot hardwareassembly 85 of all the robots in the cluster tool to avoid a collisionbetween the robots and improve system throughput by allowing all of therobots to be in motion at the same time. This so called “collisionavoidance system,” may be implemented in multiple ways, but in generalthe system controller 101 monitors the position of each of the robots byuse of various sensors positioned on the robot(s) or in the cluster toolduring the transferring process to avoid a collision. In one aspect, thesystem controller is adapted to actively alter the motion and/ortrajectory of each of the robots during the transferring process toavoid a collision and minimize the transfer path length.

B. Transfer Sequence Example

FIG. 1F illustrates one example of a substrate processing sequence 500through the cluster tool 10, where a number of process steps (e.g.,elements 501-520) may be performed after each of the transferring stepsA₁-A₁₀ have been completed. One or more of the process steps 501-520 mayentail performing vacuum and/or fluid processing steps on a substrate,to deposit a material on a surface of the substrate, to clean a surfaceof the substrate, to etch a surface of the substrate, or to exposing thesubstrate to some form of radiation to cause a physical or chemicalchange to one or more regions on the substrate. Examples of typicalprocesses that may be performed are photolithography processing steps,substrate clean process steps, CVD deposition steps, ALD depositionsteps, electroplating process steps, or electroless plating processsteps. FIG. 1G illustrates an example of the transfer steps that asubstrate may follow as it is transferred through a cluster tool that isconfigured as the cluster tool shown in FIG. 1B following the processingsequence 500 described in FIG. 1F. In this embodiment, the substrate isremoved from a pod assembly 105 (item # 105D) by the front end robotassembly 15 and is delivered to a chamber positioned at the pass-throughposition 9C following the transfer path A₁, so that the pass-throughstep 502 can be completed on the substrate. In one embodiment, thepass-through step 502 entails positioning or retaining the substrate sothat another robot could pickup the substrate from the pass-throughposition 9C. Once the pass-through step 502 has been completed, thesubstrate is then transferred to a first process chamber 531 by thethird robot assembly 11C following the transfer path A₂, where processstep 504 is completed on the substrate. After completing the processstep 504 the substrate is then transferred to the second process chamber532 by the third robot assembly 11C following the transfer path A₃.After performing the process step 506 the substrate is then transferredby the second robot assembly 11B, following the transfer path A₄, to theexchange chamber 533 (FIG. 7A). After performing the process step 508the substrate is then transferred by the rear robot assembly 40,following the transfer path A₅, to the external processing system 536where the process step 510 is performed. After performing process step510 the substrate is then transferred by a rear robot assembly 40,following the transfer path A₆, to the exchange chamber 533 where theprocess step 512 is performed. In one embodiment, the process steps 508and 512 entail positioning or retaining the substrate so that anotherrobot could pickup the substrate from the exchange chamber 533. Afterperforming the process step 512 the substrate is then transferred by thesecond robot assembly 11B, following the transfer path A₇, to theprocess chamber 534 where the process step 514 is performed. Thesubstrate is then transferred to process chamber 535 following thetransfer path A₈ using the first robot assembly 11A. After the processstep 516 is complete, the first robot assembly 11A transfers thesubstrate to a pass-through chamber positioned at the pass-throughposition 9A following the transfer path A₉. In one embodiment, thepass-through step 518 entails positioning or retaining the substrate sothat another robot could pickup the substrate from the pass-throughposition 9A. After performing the pass-through step 518 the substrate isthen transferred by the front end robot assembly 15, following thetransfer path A₁₀, to the pod assembly 105D.

In one embodiment, process steps 504, 506, 510, 514, and 516 are aphotoresist coat step, a bake/chill step, an exposure step performed ina stepper/scanner module, a post exposure bake/chill step, and a developstep, respectively, which are further described in the commonly assignedU.S. patent application Ser. No. 11/112,281, filed Apr. 22, 2005, whichis incorporated by reference herein. The bake/chill step and the postexposure bake/chill steps may be performed in a single process chamberor they may also be transferred between a bake section and a chillsection of an integrated bake/chill chamber by use of an internal robot(not shown). While FIGS. 1F-G illustrate one example of a processsequence that may be used to process a substrate in a cluster tool 10,process sequences and/or transfer sequences that are more or lesscomplex may be performed without varying from the basic scope of theinvention.

Also, in one embodiment, the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed between positions or processingchambers within in the cluster tool 10.

Second Cluster Tool Configuration

A. System Configuration

FIG. 2A is a plan view of one embodiment of cluster tool 10 that has afront end robot assembly 15, a rear robot assembly 40, a systemcontroller 101 and four robot assemblies 11 (FIGS. 9-11; elements 11A,11B, 11C, and 11D in FIG. 2A) positioned between two processing racks(elements 60 and 80), which are all adapted to perform at least oneaspect of a desired substrate processing sequence using the variousprocessing chambers found in the processing racks. The embodimentillustrated in FIG. 2A is similar to the configurations illustrated inFIGS. 1A-F except for the addition of the fourth robot assembly 11D andpass-through position 9D, thus like element numbers have been used whereappropriate. The cluster tool configuration illustrated in FIG. 2A maybe advantageous where the substrate throughput is robot limited, becausethe addition of the fourth robot assembly 11D will help to remove theburden on the other robots and also builds in some redundancy thatallows the system to process substrates when one or more of the centralrobots become inoperable. In one aspect, the side 60B of the firstprocessing rack 60, and the side 80A of the second processing rack 80are both aligned along a direction parallel to the horizontal motionassembly 90 (FIGS. 9A and 12A-C) of each of the various robot assemblies(e.g., first robot assembly 11A, second robot assembly 11B, etc.).

In one aspect, the first robot assembly 11A is adapted to access andtransfer substrates between the processing chambers in the firstprocessing rack 60 from side 60B. In one aspect, the third robotassembly 11C is adapted to access and transfer substrates between theprocessing chambers in the second processing rack 80 from side 80A. Inone aspect, the second robot assembly 11B is adapted to access andtransfer substrates between the processing chambers in the firstprocessing rack 60 from side 60B. In one aspect, the fourth robotassembly 11D is adapted to access and transfer substrates between theprocessing chambers in the second processing rack 80 from side 80A. Inone aspect, the second robot assembly 11B and fourth robot assembly 11Dare further adapted to access the processing chambers in firstprocessing rack 60 from side 60B and the second processing rack 80 fromside 80A.

FIG. 2B illustrates a plan view of the embodiment of the cluster tool 10shown in FIG. 2A, in which a robot blade 87 from the second robotassembly 11B has been extended into the a processing chamber in thefirst processing rack 60 through side 60B. The ability to extend therobot blade 87 into a processing chamber and/or retract the robot blade87 into a processing chamber is generally completed by cooperativemovement of the robot assembly 11 components, which are contained in thehorizontal motion assembly 90, a vertical motion assembly 95, and arobot hardware assembly 85, and by use of commands sent from the systemcontroller 101. As discussed above the second robot assembly 11B and thefourth robot assembly 11D along with the system controller 101 may beadapted to allow “overlap” between each of the robots in the clustertool, may allow the system controller's logical scheduler to prioritizestasks and substrate movements based on inputs from the user and varioussensors distributed throughout the cluster tool, and may also use acollision avoidance system to allow robots to optimally transfersubstrates through the system. Use of the system controller 101 tomaximize the utilization of the cluster tool can improve the clustertool's CoO, makes the wafer history more repeatable, and improves thesystem reliability.

B. Transfer Sequence Example

FIG. 2C illustrates an example of a sequence of transfer steps that maybe used to complete the processing sequence described in FIG. 1F throughthe cluster tool configuration illustrated in FIG. 2A. In thisembodiment, the substrate is removed from a pod assembly 105 (item #105D) by the front end robot assembly 15 and is delivered to a chamberpositioned at the pass-through position 9C following the transfer pathA₁, so that the pass-through step 502 can be completed on the substrate.Once the pass-through step 502 has been completed, the substrate is thentransferred to a first process chamber 531 by the third robot assembly11C following the transfer path A₂, where process step 504 is completedon the substrate. After completing the process step 504 the substrate isthen transferred to the second process chamber 532 by the fourth robotassembly 11D following the transfer path A₃. After performing theprocess step 506 the substrate is then transferred by the fourth robotassembly 11D, following the transfer path A₄, to the exchange chamber533. After performing the process step 508 the substrate is thentransferred by the rear robot assembly 40, following the transfer pathA₅, to the external processing system 536 where the process step 510 isperformed. After performing process step 510 the substrate is thentransferred by a rear robot assembly 40, following the transfer path A₆,to the exchange chamber 533 (FIG. 7A) where the process step 512 isperformed. After performing the process step 512 the substrate is thentransferred by the fourth robot assembly 11D, following the transferpath A₇, to the process chamber 534 where the process step 514 isperformed. The substrate is then transferred to process chamber 535following the transfer path A₈ using the second robot assembly 11B.After the process step 516 is complete, the first robot assembly 11Atransfers the substrate to a pass-through chamber positioned at thepass-through position 9A following the transfer path A₉. Afterperforming the pass-through step 518 the substrate is then transferredby the front end robot assembly 15, following the transfer path A₁₀, tothe pod assembly 105D.

In one aspect, the transfer path A₇ may be divided into two transfersteps which may require the fourth robot assembly 11D to pickup thesubstrate from the exchange chamber 533 and transfer it to the fourthpass-through position 9D where it is then picked up and transferred bythe second robot assembly 11B to the process chamber 534. In one aspect,each of the pass-through chambers may be accessed by any of the centralrobot assemblies (i.e., first robot assembly 11A, second robot assembly11B, third robot assembly 11C and the fourth robot assembly 11D). Inanother aspect, the second robot assembly 11B is able to pickup thesubstrate from the exchange chamber 533 and transfer it to the processchamber 534.

Also, in one embodiment the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed within in the cluster tool 10.

Third Cluster Tool Configuration

A. System Configuration

FIG. 3A is a plan view of one embodiment of cluster tool 10 that has afront end robot assembly 15, a rear robot assembly 40, a systemcontroller 101 and three robot assemblies 11 (FIGS. 9-11; elements 11A,11B, and 11C in FIG. 3A) positioned around two processing racks(elements 60 and 80), which are all adapted to perform at least oneaspect of a desired substrate processing sequence using the variousprocessing chambers found in the processing racks. The embodimentillustrated in FIG. 3A is similar to the configurations illustrated inFIGS. 1A-F except for the positioning of the first robot assembly 11Aand pass-through position 9A on side 60A of the first processing rack 60and positioning the third robot assembly 11C and pass-through position9C on the side 80B of the second processing rack 80, and thus likeelement numbers have been used where appropriate. One advantage of thiscluster tool configuration is that if one of the robots in the centralmodule 25 becomes inoperable the system can still continue to processsubstrates using the other two robots. This configuration also removes,or minimizes, the need for collision avoidance type control featureswhen the robots are transferring the substrates between processingchambers mounted in a various processing racks, since the physicaloverlap of robots that are positioned next to each other is eliminated.Another advantage of this configuration is the flexible and modulararchitecture allows the user to configure the number of processingchambers, processing racks, and processing robots required to meet thethroughput needs of the user.

In this configuration the first robot assembly 11A is adapted to accessthe processing chambers in the first processing rack 60 from side 60A,the third robot assembly 11C is adapted to access the processingchambers in the second processing rack 80 from side 80B, and the secondrobot assembly 11B is adapted to access the processing chambers in thefirst processing rack 60 from side 60B and the second processing rack 80from side 80A. In one aspect, the side 60B of the first processing rack60, and the side 80A of the second processing rack 80 are both alignedalong a direction parallel to the horizontal motion assembly 90(described below) of each of the various robot assemblies (i.e., firstrobot assembly 11A, second robot assembly 11B, third robot assembly11C).

The first robot assembly 11A, the second robot assembly 11B and thethird robot assembly 11C along with the system controller 101 may beadapted to allow “overlap” between the various robots and allow thesystem controller's logical scheduler to prioritizes tasks and substratemovements based on inputs from the user and various sensors distributedthroughout the cluster tool. Use of a cluster tool architecture andsystem controller 101 to work together to maximize the utilization ofthe cluster tool to improve CoO makes the wafer history more repeatableand improves the system reliability.

B. Transfer Sequence Example

FIG. 3B illustrates an example of a sequence of transfer steps that maybe used to complete the processing sequence described in FIG. 1F throughthe cluster tool shown in FIG. 3A. In this embodiment, the substrate isremoved from a pod assembly 105 (item # 105D) by the front end robotassembly 15 and is delivered to a chamber positioned at the pass-throughposition 9C following the transfer path A₁, so that the pass-throughstep 502 can be completed on the substrate. Once the pass-through step502 has been completed, the substrate is then transferred to a firstprocess chamber 531 by the third robot assembly 11C following thetransfer path A₂, where process step 504 is completed on the substrate.After completing the process step 504 the substrate is then transferredto the second process chamber 532 by the third robot assembly 11Cfollowing the transfer path A₃. After performing the process step 506the substrate is then transferred by the second robot assembly 11B,following the transfer path A₄, to the exchange chamber 533 (FIG. 7A).After performing the process step 508 the substrate is then transferredby the rear robot assembly 40, following the transfer path A₅, to theexternal processing system 536 where the process step 510 is performed.After performing process step 510 the substrate is then transferred by arear robot assembly 40, following the transfer path A₆, to the exchangechamber 533 (FIG. 7A) where the process step 512 is performed. Afterperforming the process step 512 the substrate is then transferred by thesecond robot assembly 11C, following the transfer path A₇, to theprocess chamber 534 where the process step 514 is performed. Thesubstrate is then transferred to process chamber 535 following thetransfer path A₈ using the second robot assembly 11B. After the processstep 516 is complete, the first robot assembly 11A transfers thesubstrate to a pass-through chamber positioned at the pass-throughposition 9A following the transfer path A₉. After performing thepass-through step 518 the substrate is then transferred by the front endrobot assembly 15, following the transfer path A₁₀, to the pod assembly105D.

Also, in one embodiment the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed within in the cluster tool 10.

Fourth Cluster Tool Configuration

A. System Configuration

FIG. 4A is a plan view of one embodiment of cluster tool 10 that has afront end robot assembly 15, a rear robot assembly 40, a systemcontroller 101 and two robot assemblies 11 (FIGS. 9-11; elements 11B,and 11C in FIG. 4A) positioned around two processing racks (elements 60and 80), which are all adapted to perform at least one aspect of adesired substrate processing sequence using the various processingchambers found in the processing racks. The embodiment illustrated inFIG. 4A is similar to the configurations illustrated in FIG. 3A exceptfor the removal of the first robot assembly 11A and pass-throughposition 9A on side 60A of the first processing rack 60, thus likeelement numbers have been used where appropriate. One advantage of thissystem configuration is that it allows easy access to chambers mountedin the first processing rack 60 and thus allows one or more processingchambers mounted in the first processing rack 60 to be taken down andworked on while the cluster tool is still processing substrates. Anotheradvantage is that the third robot assembly 11C and/or second processingrack 80 can be worked on, while substrates are being processed using thesecond robot assembly 11B. This configuration may also allow thefrequently used processing chambers in a process sequence that have ashort chamber processing time to be positioned in the second processingrack 80 so that they can be serviced by the two central robots (i.e.,elements 11B and 11C) to reduce robot transfer limited bottlenecks andthus improve system throughput. This configuration also removes orminimizes the need for collision avoidance type control features whenthe robots are transferring the substrates between processing chambersmounted in a processing rack, since the physical encroachment of eachrobot into the other's space is eliminated. Another advantage of thisconfiguration is the flexible and modular architecture allows the userto configure the number of processing chambers, processing racks, andprocessing robots required to meet the throughput needs of the user.

In this configuration the third robot assembly 11C is adapted to accessand transfer substrates between the processing chambers in the secondprocessing rack 80 from side 80B, and the second robot assembly 11B isadapted to access and transfer substrates between the processingchambers in the first processing rack 60 from side 60B and the secondprocessing rack 80 from side 80A. In one aspect, the side 60B of thefirst processing rack 60, and the side 80A of the second processing rack80 are both aligned along a direction parallel to the horizontal motionassembly 90 (described below) of each of the various robot assemblies(i.e., first robot assembly 11A, second robot assembly 11B, third robotassembly 11C).

As discussed above the second robot assembly 11B and the fourth robotassembly 11C along with the system controller 101 may be adapted toallow the system controller's logical scheduler to prioritize tasks andsubstrate movements based on inputs from the user and various sensorsdistributed throughout the cluster tool. Use of a cluster toolarchitecture and system controller 101 to work together to maximize theutilization of the cluster tool to improve CoO makes the wafer historymore repeatable and improves the system reliability.

B. Transfer Sequence Example

FIG. 4B illustrates an example of a sequence of transfer steps that maybe used to complete the processing sequence described in FIG. 1F throughthe cluster tool shown in FIG. 4A. In this embodiment, the substrate isremoved from a pod assembly 105 (item # 105D) by the front end robotassembly 15 and is delivered to a chamber positioned at the pass-throughposition 9C following the transfer path A₁, so that the pass-throughstep 502 can be completed on the substrate. Once the pass-through step502 has been completed, the substrate is then transferred to a firstprocess chamber 531 by the third robot assembly 11C following thetransfer path A₂, where process step 504 is completed on the substrate.After completing the process step 504 the substrate is then transferredto the second process chamber 532 by the third robot assembly 11Cfollowing the transfer path A₃. After performing the process step 506the substrate is then transferred by the third robot assembly 11C,following the transfer path A₄, to the exchange chamber 533 (FIG. 7A).After performing the process step 508 the substrate is then transferredby the rear robot assembly 40, following the transfer path A₅, to theexternal processing system 536 where the process step 510 is performed.After performing process step 510 the substrate is then transferred by arear robot assembly 40, following the transfer path A₆, to the exchangechamber 533 (FIG. 7A) where the process step 512 is performed. Afterperforming the process step 512 the substrate is then transferred by thesecond robot assembly 11C, following the transfer path A₇, to theprocess chamber 534 where the process step 514 is performed. Thesubstrate is then transferred to process chamber 535 following thetransfer path A₈ using the second robot assembly 11B. After the processstep 516 is complete, the second robot assembly 11B transfers thesubstrate to a pass-through chamber positioned at the pass-throughposition 9B following the transfer path A₉. After performing thepass-through step 518 the substrate is then transferred by the front endrobot assembly 15, following the transfer path A₁₀, to the pod assembly105D.

Also, in one embodiment the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed within in the cluster tool 10.

Fifth Cluster Tool Configuration

A. System Configuration

FIG. 5A is a plan view of one embodiment of cluster tool 10 that has afront end robot assembly 15, a rear robot assembly 40, a systemcontroller 101 and four robot assemblies 11 (FIGS. 9-11; elements 11A,11B, 11C and 11D in FIG. 5A) positioned around a single processing rack(elements 60), which are all adapted to perform at least one aspect of adesired substrate processing sequence using the various processingchambers found in processing rack 60. The embodiment illustrated in FIG.5A is similar to the configurations illustrated above and thus likeelement numbers have been used where appropriate. This configurationwill reduce the substrate transfer bottleneck experienced by systemsthat have three or fewer robots, due to the use of four robots that canredundantly access the process chambers mounted in the first processingrack 60. This configuration may be especially useful to remove robotlimited type bottlenecks often found when the number of processing stepsin a process sequence is large and the chamber processing time is short.

In this configuration the first robot assembly 11A and the second robotassembly 11B are adapted to access and transfer substrates between theprocessing chambers in the first processing rack 60 from side 60A, andthe third robot assembly 11C and the fourth robot assembly 11D areadapted to access and transfer substrates between the processingchambers in the first processing rack 60 from side 60B.

The first robot assembly 11A and the second robot assembly 11B, and thethird robot assembly 11C and the fourth robot assembly 11D along withthe system controller 101 may be adapted to allow “overlap” between thevarious robots, may allow the system controller's logical scheduler toprioritizes tasks and substrate movements based on inputs from the userand various sensors distributed throughout the cluster tool, and mayalso use a collision avoidance system to allow robots optimally transfersubstrates through the system. Use of a cluster tool architecture andsystem controller 101 to work together to maximize the utilization ofthe cluster tool to improve CoO makes the wafer history more repeatableand improves the system reliability.

B. Transfer Sequence Example

FIG. 5B illustrates an example of a sequence of transfer steps that maybe used to complete the processing sequence described in FIG. 1F throughthe cluster tool shown in FIG. 5A. In this embodiment, the substrate isremoved from a pod assembly 105 (item # 105D) by the front end robotassembly 15 and is delivered to a chamber positioned at the pass-throughposition 9C following the transfer path A₁, so that the pass-throughstep 502 can be completed on the substrate. Once the pass-through step502 has been completed, the substrate is then transferred to a firstprocess chamber 531 by the third robot assembly 11C following thetransfer path A₂, where process step 504 is completed on the substrate.After completing the process step 504 the substrate is then transferredto the second process chamber 532 by the fourth robot assembly 11Dfollowing the transfer path A₃. After performing the process step 506the substrate is then transferred by the fourth robot assembly 11D,following the transfer path A₄, to the exchange chamber 533 (FIG. 7A).After performing the process step 508 the substrate is then transferredby the rear robot assembly 40, following the transfer path A₅, to theexternal processing system 536 where the process step 510 is performed.After performing process step 510 the substrate is then transferred by arear robot assembly 40, following the transfer path A₆, to the exchangechamber 533 (FIG. 7A) where the process step 512 is performed. Afterperforming the process step 512 the substrate is then transferred by thefirst robot assembly 11A, following the transfer path A₇, to the processchamber 534 where the process step 514 is performed. The substrate isthen transferred to process chamber 535 following the transfer path A₈using the first robot assembly 11A. After the process step 516 iscomplete, the second robot assembly 11B transfers the substrate to apass-through chamber positioned at the pass-through position 9Bfollowing the transfer path A₉. After performing the pass-through step518 the substrate is then transferred by the front end robot assembly15, following the transfer path A₁₀, to the pod assembly 105D.

Also, in one embodiment the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed within in the cluster tool 10.

Sixth Cluster Tool Configuration

A. System Configuration

FIG. 6A is a plan view of one embodiment of cluster tool 10 that has afront end robot assembly 15, a rear robot assembly 40, a systemcontroller 101 and eight robot assemblies 11 (FIGS. 9-11; elements 11A,11B, 11C, and 11D-11H in FIG. 6A) positioned around a two processingracks (elements 60 and 80), which are all adapted to perform at leastone aspect of a desired substrate processing sequence using the variousprocessing chambers found in the processing rack. The embodimentillustrated in FIG. 6A is similar to the configurations illustratedabove and thus like element numbers have been used where appropriate.This configuration will reduce the substrate transfer bottleneckexperienced by systems that have fewer robots, due to the use of theeight robots that can redundantly access the process chambers mounted inthe processing racks 60 and 80. This configuration may be especiallyuseful to remove robot limited type bottlenecks often found when thenumber of processing steps in a process sequence is large and thechamber processing time is short.

In this configuration the first robot assembly 11A and the second robotassembly 11B are adapted to access the processing chambers in the firstprocessing rack 60 from side 60A and the seventh robot assembly 11 G andthe eighth robot assembly 11H are adapted to access the processingchambers in the second processing rack 80 from side 80B. In one aspect,the third robot assembly 11C and the fourth robot assembly 11D areadapted to access the processing chambers in the first processing rack60 from side 60B. In one aspect, the fifth robot assembly 11E and thesixth robot assembly 11F are adapted to access the processing chambersin the second processing rack 80 from side 80A. In one aspect, thefourth robot assembly 11D are further adapted to access the processingchambers in the second processing rack 80 from side 80A and the and thefifth robot assembly 11E is further adapted to access the processingchambers in the first processing rack 60 from side 60B.

The robot assemblies 11A-H along with the system controller 101 may beadapted to allow “overlap” between the various robots, may allow thesystem controller's logical scheduler to prioritizes tasks and substratemovements based on inputs from the user and various sensors distributedthroughout the cluster tool, and may also use a collision avoidancesystem to allow robots optimally transfer substrates through the system.Use of a cluster tool architecture and system controller 101 to worktogether to maximize the utilization of the cluster tool to improve CoOmakes the wafer history more repeatable and improves the systemreliability.

B. Transfer Sequence Example

FIG. 6B illustrates an example of a first processing sequence oftransfer steps that may be used to complete the processing sequencedescribed in FIG. 1F through the cluster tool shown in FIG. 6A. In thisembodiment, the substrate is removed from a pod assembly 105 (item #105D) by the front end robot assembly 15 and is delivered to apass-through chamber 9F following the transfer path A₁, so that thepass-through step 502 can be completed on the substrate. Once thepass-through step 502 has been completed, the substrate is thentransferred to a first process chamber 531 by the sixth robot assembly11F following the transfer path A₂, where process step 504 is completedon the substrate. After completing the process step 504 the substrate isthen transferred to the second process chamber 532 by the sixth robotassembly 11F following the transfer path A₃. After performing theprocess step 506 the substrate is then transferred by the sixth robotassembly 11F, following the transfer path A₄, to the exchange chamber533 (FIG. 7A). After performing the process step 508 the substrate isthen transferred by the rear robot assembly 40, following the transferpath A₅, to the external processing system 536 where the process step510 is performed. After performing process step 510 the substrate isthen transferred by a rear robot assembly 40, following the transferpath A₆, to the exchange chamber 533 (FIG. 7A) where the process step512 is performed. After performing the process step 512 the substrate isthen transferred by the fifth robot assembly 11E, following the transferpath A₇, to the process chamber 534 where the process step 514 isperformed. The substrate is then transferred to process chamber 535following the transfer path A₈ using the fifth robot assembly 11E. Afterthe process step 516 is complete, the fifth robot assembly 11E transfersthe substrate to a pass-through chamber positioned at the pass-throughposition 9E following the transfer path A₉. After performing thepass-through step 518 the substrate is then transferred by the front endrobot assembly 15, following the transfer path A₁₀, to the pod assembly105D.

FIG. 6B also illustrates an example of a second processing sequencehaving transfer steps that are completed simultaneously with the firstsequence using different processing chambers found in the secondprocessing rack 80. As illustrated in FIGS. 1C-D the first processingrack and second processing rack generally contain a number of processingchambers that are adapted to perform the same process step(s) (e.g.,CD1-8 in FIG. 1C, BC1-6 in FIG. 1D) that are used to perform a desiredprocessing sequence. Therefore, in this configuration each processingsequence may be performed using any of the processing chambers mountedin the processing racks. In one example, the second process sequence isthe same process sequence as the first processing sequence (discussedabove), which contains the same transferring steps A₁-A₁₀, depicted hereas A₁′-A₁₀′, using the seventh and eighth central robots (i.e., elements11G-11H) instead of the fifth and sixth central robot assemblies (i.e.,elements 11E-11F), respectively, as described above.

Also, in one embodiment the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed within in the cluster tool 10.

Seventh Cluster Tool Configuration

A. System Configuration

FIG. 6C is a plan view of one embodiment of cluster tool 10 that issimilar to the configuration shown in FIG. 6A except one of the robotassemblies (i.e. robot assembly 11D) has been removed to reduce thesystem width while still providing a high system throughput. Therefore,in this configuration the cluster tool 10 has a front end robot assembly15, a rear robot assembly 40, a system controller 101 and seven robotassemblies 11 (FIGS. 9-11; elements 11A-11C, and 11E-11H in FIG. 6C)positioned around a two processing racks (elements 60 and 80), which areall adapted to perform at least one aspect of a desired substrateprocessing sequence using the various processing chambers found in theprocessing rack. The embodiment illustrated in FIG. 6C is similar to theconfigurations illustrated above and thus like element numbers have beenused where appropriate. This configuration will reduce the substratetransfer bottleneck experienced by systems that have fewer robots, dueto the use of the seven robots that can redundantly access the processchambers mounted in the processing racks 60 and 80. This configurationmay be especially useful to remove robot limited type bottlenecks oftenfound when the number of processing steps in a process sequence is largeand the chamber processing time is short.

In this configuration the first robot assembly 11A and the second robotassembly 11B are adapted to access the processing chambers in the firstprocessing rack 60 from side 60A and the seventh robot assembly 11G andthe eighth robot assembly 11H are adapted to access the processingchambers in the second processing rack 80 from side 80B. In one aspect,the third robot assembly 11C and the fifth robot assembly 11E areadapted to access the processing chambers in the first processing rack60 from side 60B. In one aspect, the fifth robot assembly 11E and thesixth robot assembly 11F are adapted to access the processing chambersin the second processing rack 80 from side 80A.

The robot assemblies 11A-11C and 11E-11H along with the systemcontroller 101 may be adapted to allow “overlap” between the variousrobots, may allow the system controller's logical scheduler toprioritizes tasks and substrate movements based on inputs from the userand various sensors distributed throughout the cluster tool, and mayalso use a collision avoidance system to allow robots to optimallytransfer substrates through the system. Use of a cluster toolarchitecture and system controller 101 to work together to maximize theutilization of the cluster tool to improve CoO makes the wafer historymore repeatable and improves the system reliability.

B. Transfer Sequence Example

FIG. 6D illustrates an example of a first processing sequence oftransfer steps that may be used to complete the processing sequencedescribed in FIG. 1F through the cluster tool shown in FIG. 6C. In thisembodiment, the substrate is removed from a pod assembly 105 (item #105D) by the front end robot assembly 15 and is delivered to apass-through chamber 9F following the transfer path A₁, so that thepass-through step 502 can be completed on the substrate. Once thepass-through step 502 has been completed, the substrate is thentransferred to a first process chamber 531 by the sixth robot assembly11F following the transfer path A₂, where process step 504 is completedon the substrate. After completing the process step 504 the substrate isthen transferred to the second process chamber 532 by the sixth robotassembly 11F following the transfer path A₃. After performing theprocess step 506 the substrate is then transferred by the sixth robotassembly 11F, following the transfer path A₄, to the exchange chamber533 (FIG. 7A). After performing the process step 508 the substrate isthen transferred by the rear robot assembly 40, following the transferpath A₅, to the external processing system 536 where the process step510 is performed. After performing process step 510 the substrate isthen transferred by a rear robot assembly 40, following the transferpath A₆, to the exchange chamber 533 (FIG. 7A) where the process step512 is performed. After performing the process step 512 the substrate isthen transferred by the fifth robot assembly 11E, following the transferpath A₇, to the process chamber 534 where the process step 514 isperformed. The substrate is then transferred to process chamber 535following the transfer path A₈ using the fifth robot assembly 11E. Afterthe process step 516 is complete, the fifth robot assembly 11E transfersthe substrate to a pass-through chamber positioned at the pass-throughposition 9E following the transfer path A₉. After performing thepass-through step 518 the substrate is then transferred by the front endrobot assembly 15, following the transfer path A₁₀, to the pod assembly105D.

FIG. 6D also illustrates an example of a second processing sequencehaving transfer steps that are completed simultaneously with the firstsequence using different processing chambers found in the secondprocessing rack 80. As illustrated in FIGS. 1C-D the first processingrack and second processing rack generally contain a number of processingchambers that are adapted to perform the same process step(s) (e.g.,CD1-8 in FIG. 1C, BC1-6 in FIG. 1D) that are used to perform a desiredprocessing sequence. Therefore, in this configuration each processingsequence may be performed using any of the processing chambers mountedin the processing racks. In one example, the second process sequence isthe same process sequence as the first processing sequence (discussedabove), which contains the same transferring steps A₁-A₁₀, depicted hereas A₁′-A₁₀′, using the seventh and eighth central robots (i.e., elements11 G-11H) instead of the fifth and sixth central robot assemblies (i.e.,elements 11E-11F), respectively, as described above.

Also, in one embodiment the cluster tool 10 is not connected to or incommunication with an external processing system 536 and thus the rearrobot assembly 40 is not part of the cluster tool configuration and thetransfer steps A5-A6 and process step 510 are not performed on thesubstrate. In this configuration all of the processing steps andtransferring steps are performed within in the cluster tool 10.

Rear Robot Assembly

In one embodiment, as shown in FIGS. 1-6, the central module 25 containsa rear robot assembly 40 which is adapted to transfer substrates betweenan external module 5 and the processing chambers retained in the secondprocessing rack 80, such as an exchange chamber 533. Referring to FIG.1E, in one aspect, the rear robot assembly 40 generally contains aconventional selectively compliant articulated robot arm (SCARA) robothaving a single arm/blade 40E. In another embodiment, the rear robotassembly 40 may be a SCARA type of robot that has two independentlycontrollable arms/blades (not shown) to exchange substrates and/ortransfer substrates in groups of two. The two independently controllablearms/blade type robot may be advantageous, for example, where the robothas to remove a substrate from a desired position prior to placing thenext substrate in the same position. An exemplary two independentlycontrollable arms/blade type robot may be purchased from AsystTechnologies in Fremont, Calif. While FIGS. 1-6 illustrateconfigurations that contain a rear robot assembly 40, one embodiment ofthe cluster tool 10 does not contain a rear robot assembly 40.

FIG. 7A illustrates one embodiment of an exchange chamber 533 that maybe positioned in a support chamber 165 (FIG. 1D) in a processing rack(e.g., elements 60, 80). In one embodiment, the exchange chamber 533 isadapted to receive and retain a substrate so that at least two robots inthe cluster tool 10 can deposit or pickup a substrate. In one aspect,the rear robot assembly 40 and at least one robot in the central module25 are adapted to deposit and/or receive a substrate from the exchangechamber 533. The exchange chamber 533 generally contains a substratesupport assembly 601, an enclosure 602, and at least one access port 603formed in a wall of the enclosure 602. The substrate support assembly601 generally has a plurality of support fingers 610 (six shown in FIG.7A) which have a substrate receiving surface 611 to support and retain asubstrate positioned thereon. The enclosure 602 is generally a structurehaving one or more walls that enclose the substrate support assembly 601to control the environment around the substrates while they are retainedin the exchange chamber 533. The access port 603 is generally an openingin a wall of the enclosure 602 that allows an external robot access topickup and drop off substrates to the support fingers 610. In oneaspect, the substrate support assembly 601 is adapted to allowsubstrates to be positioned on and removed from the substrate receivingsurface 611 by two or more robots that are adapted to access theenclosure 602 at angles of at least 90 degrees apart.

In one embodiment of the cluster tool 10, illustrated in FIG. 7B, thebase 40A of the rear robot assembly 40 is mounted on a supportingbracket 40C which is connected to a slide assembly 40B, so that the base40A can be positioned at any point along the length of slide assembly40B. In this configuration the rear robot assembly 40 may be adapted totransfer substrates from processing chambers in the first processingrack 60, the second processing rack 80 and/or the external module 5. Theslide assembly 40B may generally contain a linear ball bearing slide(not shown) and linear actuator (not shown), which are well known in theart, to position the support bracket 40C and the rear robot assembly 40retained thereon. The linear actuator may be a drive linear brushlessservomotor that may be purchased from Danaher Motion of Wood Dale, Ill.As illustrated in FIG. 7B, the slide assembly 40B may be oriented in they-direction. In this configuration to prevent a collision with the robotassemblies 11A, 11B or 11C the controller will be adapted to only movethe rear robot assembly 40 when the slide assembly 40B can move withoutcolliding with the other central robot assemblies (e.g., elements 11A,11B, etc.). In one embodiment, the rear robot assembly 40 is mounted ona slide assembly 40B that is positioned so that it will not interferewith the other central robot assemblies.

Environmental Control

FIG. 8A illustrates one embodiment of the cluster tool 10 that has anattached environmental control assembly 110 that encloses the clustertool 10 to provide controlled processing environment in which to performthe various substrate processing steps found in a desired processingsequence. FIG. 8A illustrates the cluster tool 10 configuration asillustrated in FIG. 1A with an environmental enclosure positioned overthe processing chambers. The environmental control assembly 110generally contains one or more filtration units 112, one or more fans(not shown), and an optional cluster tool base 10A. In one aspect, oneor more walls 113 are added to the cluster tool 10 to enclose thecluster tool 10 and provide a controlled environment to perform thesubstrate processing steps. Generally the environmental control assembly110 is adapted to control the air flow rate, flow regime (e.g., laminaror turbulent flow) and particulate contamination levels in the clustertool 10. In one aspect, the environmental control assembly 110 may alsocontrol the air temperature, relative humidity, the amount of staticcharge in the air and other typical processing parameters that can becontrolled by use of conventional clean room compatible heatingventilation and air conditioning (HVAC) systems. In operation theenvironmental control assembly 110 draws in air from a source (notshown), or region, outside of the cluster tool 10, by use of a fan (notshown) that then sends the air through a filter 111 and then through thecluster tool 10 and out of the cluster tool 10 through the cluster toolbase 10A. In one aspect, the filter 111 is high efficiency particulateair (HEPA) filter. The cluster tool base 10A is generally the floor, orbottom region, of the cluster tool which contains a number of slots 10B(FIG. 12A) or other perforation that allow the air pushed through thecluster tool 10 by the fan(s) to exit the cluster tool 10.

FIG. 8A further illustrates one embodiment of the environmental controlassembly 110 that has multiple separate environmental control assemblies110A-C that provide controlled processing environment in which toperform the various substrate processing steps found in a desiredprocessing sequence. The separate environmental control assemblies110A-C, are each positioned over each of the robot assemblies 11 (e.g.,elements 11A, 11B, etc. in FIGS. 1-6) in the central module 25 toseparately control the air flow over the each robot assemblies 11. Thisconfiguration may be especially advantageous in the configurationsillustrated in FIGS. 3A and 4A, since the robot assemblies arephysically isolated from each other by the processing racks. Each of theseparate environmental control assemblies 110A-C generally contains afiltration unit 112, a fan (not shown) and an optional cluster tool base10A to exhaust the controlled air.

FIG. 8B illustrates a cross-sectional view of an environmental controlassembly 110 that has a single filtration unit 112 which is mounted on acluster tool 10 and is viewed using a cross-sectional plane orientedparallel to the y and z directions. In this configuration theenvironmental control assembly 110 has a single filtration unit 112, oneor more fans (not shown), and a cluster tool base 10A. In thisconfiguration the air delivered from the environmental control assembly110 into the cluster tool 10 vertically (element “A”), around theprocessing racks 60, 80 and robot assemblies 11A-C, and out the clustertool base 10A. In one aspect, the walls 113 are adapted to enclose andform a processing region inside the cluster tool 10 so that theprocessing environment around the processing chambers retained in theprocessing racks 60, 80 can be controlled by the air delivered by theenvironmental control assembly 110.

FIG. 8C illustrates a cross-sectional view of an environmental controlassembly 110 that has multiple separate environmental control assemblies110A-C that are mounted on a cluster tool 10 and are viewed using across-sectional plane oriented parallel to the y and z directions (seeFIG. 1A). In this configuration the environmental control assembly 110contains a cluster tool base 10A, three environmental control assemblies110A-C, a first processing rack 60 that extends to or above the lowersurface 114 of the environmental control assemblies 110A-C, and a secondprocessing rack 80 that extends to or above the lower surface 114 of theenvironmental control assemblies 110A-C. In general the threeenvironmental control assemblies 110A-C will each contain one or morefans (not shown) and a filter 111. In this configuration the airdelivered from each of the environmental control assemblies 110A-C intothe cluster tool 10 vertically (element “A”), between the processingracks 60, 80 and robot assemblies 11A-C, and out the cluster tool base10A. In one aspect, the walls 113 are adapted to enclose and form aprocessing region inside the cluster tool 10 so that the processingenvironment around the processing chambers retained in the processingracks 60, 80 can be controlled by the air delivered by the environmentalcontrol assembly 110.

In another embodiment, the cluster tool 10 is placed in clean roomenvironment that is adapted to deliver low particulate containing air ata desired velocity through the cluster tool 10 and then out the clustertool base 10A. In this configuration the environmental control assembly110 is generally not needed, and thus is not used. The ability tocontrol the properties air and environment around the processingchambers retained in the cluster tool 10 is an important factor in thecontrol and/or minimization of the accumulation of particles, which cancause device yield problems caused by particulate contamination.

Robot Assemblies

In general the various embodiments of the cluster tool 10 describedherein have particular advantage over prior art configurations due tothe reduced cluster tool foot print created by the reduced size of therobot assemblies (e.g., element 11 in FIG. 9A) and a robot design thatminimizes the physical encroachment of a robot into a space occupied byother cluster tool components (e.g., robot(s), process chambers) duringthe process of transferring a substrate. The reduced physicalencroachment prevents collisions of the robot with other foreigncomponents. While reducing the footprint of the cluster tool, theembodiments of the robot described herein, also has particular advantagedue to the reduced number of axes that need to be controlled to performthe transferring motion. This aspect is important since it will improvethe reliability of the robot assemblies and thus the cluster tool. Theimportance of this aspect may be better understood by noting that thereliability of a system is proportional to the product of thereliability of each component in the system. Therefore, a robot havingthree actuators that have a 99% up-time is always better than a robotthat has four actuators having 99% up-time, since the system up-time forthree actuators each having 99% up-time is 97.03% and for four actuatorseach having 99% up-time is 96.06%.

The embodiments of the cluster tool 10 described herein also haveparticular advantage over prior art configurations due to the reducednumber of pass-through chambers (e.g., elements 9A-C in FIG. 1B),required to transfer a substrate though the cluster tool. The prior artcluster tool configurations commonly install two or more pass-throughchambers, or of interim substrate retaining stations, in the processingsequence so that the cluster tool robots can transfer a substratebetween one robot that is centrally positioned between one or moreprocessing chambers to another robot that is centrally positionedbetween one or more other processing chambers during the processingsequence. The process of successively placing a substrate in multiplepass-through chambers that will not perform a subsequent processing stepwastes time, decreases the availability of the robot(s), wastes space inthe cluster tool, and increases the wear on the robot(s). The additionof the pass-through steps will also adversely affect device yield, dueto the increase in the number of substrate handoffs which will increasethe amount of backside particle contamination. Also, substrateprocessing sequences that contain multiple pass-through steps willinherently have different substrate wafer histories, unless the timespent in the pass-through chamber is controlled for every substrate.Controlling the time in the pass-through chamber will increase thesystem complexity, due to an added process variable, and it will likelyhurt the maximum achievable substrate throughput. The aspects of theinvention, described herein, avoid these pitfalls of the prior artconfigurations, since the cluster tool configuration generally only hasthe pass-through steps (e.g., steps 502 and 518 in FIG. 1F) before anyprocessing has occurred on a substrate and after all of the processingsteps have been completed on a substrate, and thus will generally havelittle to no affect on the substrates wafer history and will notsignificantly add to the processing sequence substrate transfer time,due to the removal of pass-through steps between the processing steps.

In a case where the system throughput is robot limited, the maximumsubstrate throughput of the cluster tool is governed by the total numberof robot moves to complete the process sequence and the time it takes tomake the robot move. The time it takes a robot to make a desired move isusually limited by robot hardware, distance between processing chambers,substrate cleanliness concerns, and system control limitations.Typically the robot move time will not vary much from one type of robotto another and is fairly consistent industry wide. Therefore, a clustertool that inherently has fewer robot moves to complete the processingsequence will have a higher system throughput than a cluster tool thatrequires more moves to complete the processing sequence, such as clustertools that contains multiple pass-through steps.

Cartesian Robot Configuration

FIG. 9A illustrates one embodiment of a robot assembly 11 that may beused as one or more of the robot assemblies 11 (e.g., elements 11A-Hshown in FIGS. 1-6 above). The robot assembly 11 generally contains arobot hardware assembly 85, one or more vertical robot assemblies 95 andone or more horizontal robot assemblies 90. A substrate can thus bepositioned in any desired x, y and z position in the cluster tool 10 bythe cooperative motion of the robot hardware assemblies 85, verticalrobot assemblies 95 and horizontal robot assemblies 90, from commandssent by the system controller 101.

The robot hardware assembly 85 generally contains one or more transferrobot assemblies 86 that are adapted to retain, transfer and positionone or more substrates by use of commands sent from the systemcontroller 101. In one embodiment, the transfer robot assemblies 86shown in FIGS. 9-11 are adapted to transfer the substrates in ahorizontal plane, such as a plane that includes the X and Y directionsillustrated in FIG. 11A, due to the motion of the various transfer robotassemblies 86 components. In one aspect, the transfer robot assemblies86 are adapted to transfer a substrate in a plane that is generallyparallel to the substrate supporting surface 87C (FIG. 10C) of the robotblades 87. FIG. 10A illustrates one embodiment of the robot hardwareassembly 85 that contains a single transfer robot assembly 86 that maybe adapted to transfer substrates. FIG. 10B illustrates one embodimentof the robot hardware assembly 85 that contains two transfer robotassemblies 86 that are positioned in an opposing orientation to eachother so that the blades 87A-B (and first linkages 310A-310B) can beplaced a small distance apart. The configuration shown in FIG. 10B, or“over/under” type blade configuration, may be advantageous, for example,where it is desired to remove a substrate from a processing chamberprior to placing the next substrate to be processed in the sameprocessing chamber, without causing the robot hardware assembly 85 toleave its basic position to move the “removed” substrate to anotherchamber (i.e., “swap” substrates). In another aspect, this configurationmay allow the robot to fill up all of the blades and then transfer thesubstrates in groups of two or more substrates to a desired location inthe tool. The process of grouping substrates in groups of two or morecan help to improve substrate throughput in the cluster tool by reducingthe number of robot movements required to transfer the substrates. Whiletransfer robot assemblies 86 depicted in FIGS. 10A-B are the two barlinkage robot 305 type of robot (FIG. 10C), this configuration is notintended to be limiting as to the orientation and type of robot assemblythat may be used in conjunction with the embodiments discussed herein.In general, the embodiment of the robot hardware assembly 85 that hastwo transfer robot assemblies 86, as illustrated in FIG. 10B, will havetwo transfer robot assemblies 86 which contain the same basiccomponents, and thus the discussion of a single transfer robot assembly86 hereafter, is intended to also describe the components found in thetwo robot assembly aspect(s).

One advantage of the cluster tool and robot configurations illustratedin FIGS. 9-11, is that the size of the region that surrounds a transferrobot assembly 86 in which the robot components and substrate are freeto move without colliding with other cluster tool components external tothe robot assembly 11, is minimized. The area in which the robot andsubstrate are free to move is known as the “transferring region”(element 91 in FIG. 11C). The transferring region 91 may generally bedefined as volume (x, y and z directions) in which the robot is free tomove while a substrate is retained on a robot blade without collidingwith other cluster tool components. While the transferring region may bedescribed as a volume, often the most important aspect of thetransferring region is the horizontal area (x and y-directions) whichthe transferring region occupies, since it directly affects a clustertool's footprint and CoO. The horizontal area of the transferring regionis an important factor in defining the footprint of the cluster tool,since the smaller the horizontal components of the transferring region,the closer the various robots assemblies (e.g., elements 11A, 11B, 11C,etc. in FIGS. 1-6) can be placed together or the closer a robot can beplaced to a processing rack. One factor in the defining size of thetransferring region is the need to assure that the transferring regionis large enough to reduce or prevent a robot's physical encroachmentinto the space occupied by other cluster tool components. Theembodiments described herein have particular advantage over the priorart due to the way in which the embodiments retract the robots assembly86 components into the transferring region oriented along the transferdirection (x-direction) of the horizontal motion assembly 90.

Referring to FIG. 11J, the horizontal area can generally be broken intotwo components the width “W₁” (y-direction) and the length “L”(x-direction). The embodiments described herein have further advantagedue to the reduced width “W₁” of the clearance area surrounding therobot to assure that the robot can reliably position a substrate into aprocessing chamber. The benefits of the reduced width “W₁,” improvementover conventional multi-bar linkage selective compliance assembly robotarm (SCARA) type robots can be understood by noting that conventionalSCARA robots (e.g., item CR in FIG. 11K) generally have arms (e.g.,element A₁) that when retracted extends a distance from the center ofthe robot (e.g., item C), which increases the relative spacing of therobots to each other (i.e., width “W₂”), since the area around the robotmust be clear so that the arm components can be rotationally orientedwithout interfering with other cluster tool components (e.g., otherrobots, processing rack components). The conventional SCARA type robotconfigurations are also more complex than some of the embodimentsdescribed herein since they also have more axes to control to cause thesubstrate to be oriented and positioned in a processing chamber.Referring to FIG. 11J, in one aspect, the width W₁ of the transferringregion 91 is between about 5 and about 50 percent larger than the sizeof the substrate (i.e., substrate “S” FIG. 11J). In one example, wherethe substrate is a 300 mm semiconductor wafer the width W₁ of thetransferring region would be between about 315 mm and about 450 m, andpreferably between about 320 mm and about 360 mm. Referring to FIG. 1B,in one example, the distance between the side 60B of the firstprocessing rack 60 and the side 80A of the second processing rack 80 maybe about 945 mm (e.g., 315%) for a 300 mm substrate processing tool. Inanother example, the distance between the side 60B of the firstprocessing rack 60 and the side 80A of the second processing rack 80 maybe about 1350 mm (e.g., 450%) for a 300 mm substrate processing tool. Itshould be noted that the transferring region is generally intended todescribe a region around the robot in which it is able move once therobot blade has been retracted after picking up the substrate in adesired position until it moves to a starting position (SP) outside thenext processing chamber in the processing sequence.

Two Bar Linkage Robot Assembly

FIGS. 10A and 10C, illustrates one embodiment of a two bar linkage robot305 type of transfer robot assembly 86 that generally contains a supportplate 321, a first linkage 310, a robot blade 87, a transmission system312 (FIG. 10C), an enclosure 313 and a motor 320. In this configurationthe transfer robot assembly 86 is attached to the vertical motionassembly 95 through the support plate 321 which is attached to thevertical actuator assembly 560 (FIG. 13A). FIG. 10C illustrates a sidecross-sectional view of one embodiment of the two bar linkage robot 305type of transfer robot assembly 86. The transmission system 312 in thetwo bar linkage robot 305 generally contains one or more powertransmitting elements that are adapted to cause the movement of therobot blade 87 by motion of the power transmitting elements, such as bythe rotation of motor 320. In general, the transmission system 312 maycontain gears, pulleys, etc. that are adapted to transfer rotational ortranslation motion from one element to another. In one aspect thetransmission system 312, as shown in FIG. 10C, contains a first pulleysystem 355 and a second pulley system 361. The first pulley system 355has a first pulley 358 that is attached to the motor 320, a secondpulley 356 attached to the first linkage 310, and a belt 359 thatconnects the first pulley 358 to the second pulley 356, so that themotor 320 can drive the first linkage 310. In one aspect, a plurality ofbearings 356A are adapted to allow the second pulley 356 to rotate aboutthe axis V₁ of the third pulley 354.

The second pulley system 361 has a third pulley 354 that is attached tosupport plate 321, a fourth pulley 352 that is attached to the blade 87and a belt 362 that connects the third pulley 354 to the fourth pulley352 so that the rotation of the first linkage 310 causes the blade 87 torotate about the bearing axis 353 (pivot V₂ in FIG. 11A) coupled to thefirst linkage 310. When in transferring a substrate the motor drives thefirst pulley 358 which causes the second pulley 356 and first linkage310 to rotate, which causes the fourth pulley 352 to rotate due to theangular rotation of the first linkage 310 and belt 362 about thestationary third pulley 354. In one embodiment, the motor 320 and systemcontroller 101 are adapted to form a closed-loop control system thatallows the angular position of the motor 320 and all the componentsattached thereto to be controlled. In one aspect the motor 320 is astepper motor or DC servomotor. 132) In one aspect, the transmissionratio (e.g., ratio of diameters, ratio of the number of gear teeth) ofthe first pulley system 355 and second pulley system 361 may be designedto achieve a desired shape and resolution of the path (e.g., element P₁in FIG. 11C or 11D) the substrate moves along as it is positioned by atransfer robot assembly 86. The transmission ratio will be hereafterdefined as the driving element size to the driven element size, or inthis case, for example, the ratio of number of teeth of on third pulley354 to the number of teeth on the fourth pulley 352. Therefore, forexample, where the first linkage 310 is rotated 270 degrees which causesthe blade 87 to rotate 180 degrees equates to a 0.667 transmission ratioor alternately a 3:2 gear ratio. The term gear ratio is meant to denotethat D₁ number of turns of the first gear causes D₂ number of turns ofthe second gear, or an D₁:D₂ ratio. Therefore, a 3:2 ratio means thatthree turns of the first gear will cause two turns of the second gearand thus the first gear must be about two thirds the size of the secondgear. In one aspect, the gear ratio of the third pulley 354 to thefourth pulley 352 is between about 3:1 to about 4:3, preferably betweenabout 2:1 and about 3:2.

FIG. 10E illustrates another embodiment of a two bar linkage robot 305type of transfer robot assembly 86 that generally contains a supportplate 321, a first linkage 310, a robot blade 87, a transmission system312 (FIG. 10E), an enclosure 313, a motor 320 and a second motor 371.The embodiment illustrated in FIG. 10E is similar to the embodimentshown in FIG. 10C except in this configuration the rotational positionof third pulley 354 can be adjusted by use of the second motor 371 andcommands from the controller 101. Since FIGS. 10C and 10E are similarlike numbers are used for clarity. In this configuration the transferrobot assembly 86 is attached to the vertical motion assembly 95 throughthe support plate 321 which is attached to the vertical actuatorassembly 560 (FIG. 13A). FIG. 10E illustrates a side cross-sectionalview of one embodiment of the two bar linkage robot 305 type of transferrobot assembly 86. The transmission system 312 in the two bar linkagerobot 305 generally contains two power transmitting elements that areadapted to cause the movement of the robot blade 87 by motion of themotor 320 and/or the second motor 371. In general, the transmissionsystem 312 may contain gears, pulleys, etc. that are adapted to transferrotational or translation motion from one element to another. In oneaspect, the transmission system 312 contains a first pulley system 355and a second pulley system 361. The first pulley system 355 has a firstpulley 358 that is attached to the motor 320, a second pulley 356attached to the first linkage 310, and a belt 359 that connects thefirst pulley 358 to the second pulley 356, so that the motor 320 candrive the first linkage 310. In one aspect, a plurality of bearings 356Aare adapted to allow the second pulley 356 to rotate about the axis V₁of the third pulley 354. In one aspect, not shown in FIG. 10E, thebearings 356A are mounted on a feature formed on the support plate 321rather than the third pulley 354 as shown in FIG. 10E.

The second pulley system 361 has a third pulley 354 that is attached tothe second motor 371, a fourth pulley 352 that is attached to the blade87 and a belt 362 that connects the third pulley 354 to the fourthpulley 352 so that the rotation of the first linkage 310 causes theblade 87 to rotate about the bearing axis 353 (pivot V₂ in FIG. 11A)coupled to the first linkage 310. The second motor 371 is mounted on thesupport plate 321. When transferring a substrate the motor 320 drivesthe first pulley 358 which causes the second pulley 356 and firstlinkage 310 to rotate, which causes the fourth pulley 352 to rotate dueto the angular rotation of the first linkage 310 and belt 362 about thethird pulley 354. In this configuration, versus the configuration shownin FIG. 10C, the third pulley can be rotated while the motor 320 isrotating the first linkage 310 which allows the gear ratio between thethird pulley 354 and the fourth pulley 352 to be varied by adjusting therelative motion between the third pulley 354 and the fourth pulley 352.One will note that the gear ratio affects the robot blade 87 motionrelative to the first linkage 310. In this configuration the gear ratiois not fixed by the size of the gears, and may be changed in differentparts of the robot blade transferring motion to achieve a desired robotblade transfer path (see FIG. 11D). In one embodiment, the motor 320,the second motor 371 and the system controller 101 are adapted to form aclosed-loop control system that allows the angular position of the motor320, the angular position of the second motor 371 and all the componentsattached to these elements to be controlled. In one aspect, the motor320 and the second motor 371 are a stepper motor or DC servomotor.

FIGS. 11A-D illustrate a plan view of one embodiment of a robot assembly11 that uses a two bar linkage robot 305 configuration to transfer andposition substrates in a desired position in a second process chamber532 retained in the cluster tool 10. The two bar linkage robot 305generally contains a motor 320 (FIG. 10A-C), a first linkage 310 and arobot blade 87 that are connected so that rotational motion of the motor320 causes the first linkage 310 to rotate which then causes the robotblade 87 to rotate and/or translate along a desired path. The advantageof this configuration is ability of the robot to transfer a substrate toa desired position in the cluster tool without the components of therobot extending into a space that is currently occupied, or will beoccupied, by another robot or system component.

FIGS. 11A-C illustrates the motion of a transfer robot assembly 86,contained in a robot hardware assembly 85, by illustrating a number ofsequential snapshots in time (e.g., T₀-T₂ corresponding to FIGS. 11A-C,respectively) of the position of the various transfer robot assembly 86components as a substrate is transferred into a processing chamber 532.Referring to FIG. 11A, at time T₀ the transfer robot assembly 86 isgenerally positioned in a desired vertical orientation (z-direction) byuse of the vertical motion assembly 95 components and in a desiredhorizontal position (x-direction) by use of the horizontal motionassembly 90 components. The robot position at T₀, shown in FIG. 11A,will be referred to herein as the starting position (item SP). Referringto FIG. 11B, at time T₁ the first linkage 310, in the two bar linkagerobot 305, is pivoted about pivot point V₁ thus causing the coupledrobot blade 87 to translate and rotate about a pivot point V₂, while theposition of the transfer robot assemblies 86 in the x-direction isadjusted by use of the horizontal motion assembly 90 components and thesystem controller 101. Referring to FIG. 11C, at time T₂ the robot blade87 has been extended a desired distance (element Y₁) in the y-directionfrom the centerline C₁ of the transfer region 91 and is positioned in adesired x-direction position (element X₁) to place a substrate in adesired final position (item FP), or handoff position in the processingchamber 532. Once the robot has positioned the substrate in the finalposition the substrate can then be transferred to the process chambersubstrate receiving components, such as lift pins or other substratesupporting components (e.g., elements 532A in FIG. 11A). Aftertransferring the substrate to the process chamber receiving componentsthe robot blade may then be retracted following the steps describedabove but in reverse.

FIG. 11C further illustrates an example of one possible path (item P₁)of the center of the substrate as it is moved from the starting positionto the final position, as illustrated in FIGS. 11A-C above. In oneaspect of the invention, the shape of the path can be varied by theadjustment of the rotational position of the first linkage 310 relativeto the position of the transfer robot assembly 86 along the x-directionby use of the horizontal motion assembly 90. This feature has advantagesince the shape of the curve can be specifically adapted to allow arobot blade 87 to access the processing chamber without colliding withthe various process chamber substrate receiving components (e.g.,elements 532A) or encroaching the transfer region 91 of the otherrobots. This advantage becomes especially apparent when a processingchamber is configured to be accessed from multiple different directions,or orientations, which thus limit the position and orientation of thesubstrate receiving components that can be used to reliably support asubstrate and prevent a collision between the robot blade 87 and thesubstrate receiving components.

FIG. 11D illustrates a few examples of possible paths P₁-P₃ that may beused to transfer a substrate into a desired position in the processingchamber 532. The paths P₁-P₃ illustrated in FIGS. 11D-F are intended toshow the motion of the center of the substrate, or center of thesubstrate supporting area of the robot blade 87, as it is positioned bythe robot assembly 11 components. The substrate transfer path P₂illustrated in FIG. 11D illustrates the path of a substrate when thesecond pulley system 361 of a transfer robot assembly 86 has atransmission ratio of 2:1. Since the motion of the substrate when usinga 2:1 transmission ratio is a straight line, this configuration canremove the need to translate the robot hardware assembly 85 in theX-direction while extending the robot blade 87 in the Y-direction. Thebenefits of the reduced complexity of motion in this configuration mayin some cases be tempered by the inability to design the reliablesubstrate receiving components that will not interfere with the robotblade 87 as the substrate is transferred into the processing chamberfrom various different sides of the processing chamber.

FIGS. 11E-11F illustrate a multistep transfer motion of a substrate intothe processing chamber 532. In one embodiment, the multistep transfermotion is broken up into three transfer paths (paths P₁-P₃) which can beused to transfer the substrate into the processing chamber 532 (FIG.11E) or out of the processing chamber (FIG. 11F). This configuration maybe especially useful to reduce the high accelerations experienced by thesubstrate and robot assembly 11 during the transfer process and alsoreduce the complexity of the robot motion by use of single axis controlas much as possible during the transfer process. The high accelerationsexperienced by the robot can generate vibrations in the robot assemblywhich can affect the transfer processes positional accuracy, thereliability of the robot assembly and possibly movement of the substrateon the robot blade. It is believed one cause of the high accelerationsexperienced by the robot assembly 11 occurs when coordinated motions areused to transfer the substrate. The term “coordinated motions” as usedherein is intended to describe the movement of two or more axes (e.g.,transfer robot assemblies 86, horizontal motion assembly 90, verticalmotion assembly 95) at the same time to cause a substrate to move fromone point to the next.

FIG. 11E illustrates a three transfer path multistep transfer motionwhich is used to transfer a substrate to the substrate receivingcomponents 532A found in the processing chamber 532. Before themultistep transfer motion process is performed the transfer robotassembly 86 is generally positioned in the starting position (SP in FIG.11E) which may require the substrate to be moved to a desired verticalorientation (z-direction) by use of the vertical motion assembly 95components and in a desired horizontal position (x-direction) by use ofthe horizontal motion assembly 90 components. In one aspect, once thesubstrate is in the starting position the substrate is then moved alongpath P₁ to the final position (FP) by use of the transfer robotassemblies 86, the horizontal motion assembly 90 and the systemcontroller 101. In another aspect, the substrate is positioned alongpath P₁ using a reduced number of axes of control, such as only one axisof control. For example, a single axis of control may be completed bycausing the movement of the robot blade, and substrate, by the controlof the transfer robot assembly 86 which is in communication with thecontroller 101. In this configuration the use of a single axis cangreatly simplify the control of the substrate or robot blade motion andreduce the time it takes to move from the starting point to theintermediate position. The next step in the multistep transfer motionprocess the substrate is then transferred to the process chambersubstrate receiving components, such as lift pins or other substratesupporting components (e.g., elements 532A in FIG. 11A) by moving in thez-direction by use of the vertical motion assembly 95 components or bymoving the substrate receiving components 532A vertically by use of ansubstrate receiving component actuator (not shown). In one aspect, asshown in FIGS. 11E and 11F, the transfer robot assembly 86 is adapted totranslate the substrate W in the plane that that is parallel to the Xand Y directions, as illustrated by paths P1 and P3.

After transferring the substrate to the process chamber receivingcomponents the robot blade may then be retracted following paths P₂ andP₃. The path P₂, in some cases may require a coordinated motion betweenthe transfer robot assembly 86 and the horizontal motion assembly 90 toassure that the robot blade 87 does not hit the substrate supportingcomponents 532A as it is being retracted from the processing chamber532. In one aspect, as shown in FIG. 11E, the path P₂, which describesthe motion of the center of the substrate supporting area of the robotblade 87, is a linear path which extends from the final position (FP) tosome intermediate point (IP) between the final position and the endpoint (EP) position. In general, the intermediate point is a point wherethe robot blade has been retracted far enough so that it will not comeinto contact with any of the chamber components when it is moved in asimplified or accelerated motion along path P₃ to the endpoint pointposition. In one aspect, once the robot blade is in the intermediatepoint position the substrate is then moved along path P₃ to the endpoint by use of the transfer robot assemblies 86, the horizontal motionassembly 90 and the system controller 101. In one aspect, the substrateis positioned at the end point (EP) by use of only one axis of control,such as by motion of the transfer robot assemblies 86 which is incommunication with the controller 101. In this configuration the use ofa single axis can greatly simplify the control of the motion and reducethe time it takes to move from the intermediate point (IP) to the endpoint (EP) position.

FIG. 11F illustrates a three transfer path multistep transfer motionwhich is used to remove a substrate from the substrate receivingcomponents 532A found in the processing chamber 532. Before themultistep transfer motion process, shown in FIG. 11F, is performed thetransfer robot assembly 86 is generally positioned in the startingposition (SP in FIG. 11F) which may require the substrate to be moved toa desired vertical orientation (z-direction) by use of the verticalmotion assembly 95 components and in a desired horizontal position(x-direction) by use of the horizontal motion assembly 90 components. Inone aspect, once the substrate is in the starting position the substrateis then moved along path P₁ to the intermediate position (IP) by use ofthe transfer robot assemblies 86, the horizontal motion assembly 90 andthe system controller 101. In general, the intermediate point is a pointwhere the robot blade has been inserted far enough so that it will notcome into contact with any of the chamber components as it moved in asimplified or accelerated motion along path P₁ to the intermediatepoint. In another aspect, the substrate is positioned along path P₁using a reduced number of axes of control, such as only one axis ofcontrol. For example, a single axis of control may be completed bycausing the movement of the robot blade, and substrate, by the controlof the transfer robot assembly 86 which is in communication with thecontroller 101. In this configuration the use of a single axis cangreatly simplify the control of the substrate or robot blade motion andreduce the time it takes to move from the starting point to theintermediate position.

After transferring the substrate to the intermediate position the robotblade may then be further inserted into the chamber following paths P₂.The path P₂, in some cases may require a coordinated motion between thetransfer robot assembly 86 and the horizontal motion assembly 90 toassure that the robot blade 87 does not hit the substrate supportingcomponents 532A as it is being extended into the processing chamber 532.In one aspect, as shown in FIG. 11F, the path P₂, which describes themotion of the center of the substrate supporting area of the robot blade87, is a linear path which extends from the intermediate point (IP) tothe final position (FP). After the robot blade is positioned in thefinal position the substrate is then removed from the process chambersubstrate receiving components 532A by moving the transfer robotassembly 86 in the z-direction by use of the vertical motion assembly 95or by moving the substrate receiving components 532A vertically by useof an substrate receiving component actuator (not shown).

After removing the substrate from the process chamber receivingcomponents the robot blade may then be retracted following paths P₃. Thepath P₃, in some cases may require a coordinated motion between thetransfer robot assembly 86 and the horizontal motion assembly 90. In oneaspect, the substrate is positioned at the end point (EP) by use of onlyone axis of control, such as by motion of a transfer robot assembly 86which is in communication with the controller 101. In this configurationthe use of a single axis can greatly simplify the control of the motionand reduce the time it takes to move from the final position (FP) to theend point (EP) position. In one aspect, as shown in FIG. 11F, the pathP₃, which describes the motion of the center of the substrate supportingarea of the robot blade 87, is a non-linear path which extends from thefinal position (FP) to some end point (EP).

Single Axis Robot Assembly

FIGS. 10D and 11G-I illustrate another embodiment of a robot assembly 11wherein the transfer robot assembly 86A is a single axis linkage 306(FIG. 10D) configuration to transfer and position substrates in adesired position in a second process chamber 532 retained in the clustertool 10. The single axis linkage 306 generally contains a motor 307(FIG. 10D) and a robot blade 87 that are connected so that rotationalmotion of the motor 320 causes the robot blade 87 to rotate. Theadvantage of this configuration is ability of the robot to transfer asubstrate to a desired position in the cluster tool using only a lesscomplicated and more cost effective single axis to control the blade 87,while also reducing the chance of extending the robot components into aspace that could be occupied by another robot during the transferringprocess.

FIG. 10D illustrates a side cross-sectional view of a single axislinkage 306, which generally contains a motor 307, a support plate 321and a robot blade 87 that are connected to the motor 307. In oneembodiment, as shown in FIG. 10D, the robot blade 87 is connected to afirst pulley system 355. The first pulley system 355 has a first pulley358 that is attached to the motor 320, a second pulley 356 attached tothe robot blade 87, and a belt 359 that connects the first pulley 358 tothe second pulley 356. In this configuration the second pulley 356 ismounted on the pivot 364 that is attached to the support plate 321through and bearings 354A, so that the motor 307 can rotate the robotblade 87. In one embodiment of the single axis linkage 306, the robotblade 87 is directly coupled to the motor 307 to reduce the number ofrobot components, reduce the robot assembly cost and complexity, andreduce the need to maintain the components in the first pulley system355. The single axis linkage 306 may be advantageous due to thesimplified motion control system and thus improved robot and systemreliability.

FIGS. 11G-J are plan views of the single axis linkage 306 type oftransfer robot assembly 86, which illustrate the motion of the singleaxis linkage 306, by showing a number of sequential snapshots in time(e.g., items T₀-T₂) of the position of the various transfer robotassembly 86 components as a substrate is transferred into a processingchamber 532. Referring to FIG. 11G, at time T₀ the transfer robotassembly 86 is generally positioned in a desired vertical orientation(z-direction) by use of the vertical motion assembly 95 components andin a desired horizontal position (x-direction) by use of the horizontalmotion assembly 90 components. The robot position at T₀, shown in FIG.11C, will be referred to herein as the starting position (item SPdiscussed above). Referring to FIG. 11H, at time T₁ the robot blade 87is pivoted about pivot point V₁ thus causing the robot blade 87 torotate, while the position of the transfer robot assemblies 86 isadjusted in the x-direction by use of the system controller 101.Referring to FIG. 11I, at time T₂ the robot blade 87 has been rotated toa desired angle and the robot assembly has been positioned in a desiredx-direction position so that the substrate is in a desired finalposition (item FP), or handoff position, in the processing chamber 532.FIG. 11D, discussed above, also illustrates a few examples of possiblepaths P₁-P₃ that may be used to transfer a substrate into a desiredposition in the processing chamber 532 by use of the single axis linkage306. After transferring the substrate to the process chamber receivingcomponents the robot blade may then be retracted following the stepsdescribed above but in reverse.

Horizontal Motion Assembly

FIG. 12A illustrates a cross-sectional view of one embodiment of thehorizontal motion assembly 90 taken along a plane parallel to they-direction. FIG. 12B is a side cross-sectional view of one embodimentof the robot assembly 11 that has been centrally cut down the length ofthe horizontal motion assembly 90. The horizontal motion assembly 90generally contains an enclosure 460, an actuator assembly 443 and a sledmount 451. The actuator assembly 443 generally contains at least onehorizontal linear slide assembly 468 and a motion assembly 442. Thevertical motion assembly 95 is attached to the horizontal motionassembly 90 through the sled mount 451. The sled mount 451 is astructural piece that supports the various loads created as the verticalmotion assembly 95 is positioned by the horizontal motion assembly 90.The horizontal motion assembly 90 generally contains two horizontallinear slide assemblies 468 that each have a linear rail 455, a bearingblock 458 and a support mount 452 that support the weight of the sledmount 451 and vertical motion assembly 95. This configuration thusallows for a smooth and precise translation of the vertical motionassembly 95 along the length of the horizontal motion assembly 90. Thelinear rail 455 and the bearing block 458 may be linear ball bearingslides or a conventional linear guide, which are well known in the art.

Referring to FIGS. 12A-B, the motion assembly 442 generally containssled mount 451, a horizontal robot actuator 367 (FIGS. 10A and 12A), adrive belt 440, and two or more drive belt pulleys 454A that are adaptedto control the position of the vertical motion assembly 95 along thelength of the horizontal motion assembly 90. In general, the drive belt440 is attached to the sled mount 451 (e.g., bonded, bolted or clamped)to form a continuous loop that runs along the length of the horizontalmotion assembly 90 and is supported at the ends of the horizontal motionassembly 90 by the two or more drive belt pulleys 454A. FIG. 12Billustrates one configuration that has four drive belt pulleys 454A. Inone embodiment, the horizontal robot actuator 367 is attached to one ofthe drive belt pulleys 454A so that rotational motion of the pulley 454Awill cause the drive belt 440 and the sled mount 451, which is attachedto the vertical motion assembly 95, to move along the horizontal linearslide assemblies 468. In one embodiment, the horizontal robot actuator367 is a direct drive linear brushless servomotor, which is adapted tomove the robot relative to the horizontal linear slide assembly 468.

The enclosure 460 generally contains a base 464, one or more exteriorwalls 463 and an enclosure top plate 462. The enclosure 460 is adaptedto cover and support the components in the horizontal motion assembly90, for safety and contamination reduction reasons. Since particles aregenerated by mechanical components that roll, slide, or come in contactwith each other, it is important to assure that the components in thehorizontal motion assembly 90 do not contaminate the substrate surfacewhile the substrates are transferred through the cluster tool 10. Theenclosure 460 thus forms an enclosed region that minimizes the chancethat particles generated inside the enclosure 460 will make their way tothe surface of a substrate. Particulate contamination has direct effecton device yield and thus CoO of the cluster tool.

The enclosure top plate 462 contains a plurality of slots 471 that allowthe plurality of support mounts 452 in the horizontal linear slideassemblies 468 to extend through the enclosure top plate 462 and connectto the sled mount 451. In one aspect, the width of the slots 471 (sizeof the opening in the y-direction) are sized to minimize the chance ofparticles making their way outside of the horizontal motion assembly 90.

The base 464 of the enclosure 460 is a structural member that isdesigned to support the loads created by the weight of the sled mount451 and vertical motion assembly 95, and loads created by the movementof the vertical motion assembly 95. In one aspect, the base 464 furthercontains a plurality of base slots 464A that are positioned along thelength of the horizontal motion assembly 90 to allow air entering theslots 471 of the enclosure top plate 462 to exit the enclosure throughthe base slots 464A and out the slots 10B formed in the cluster toolbase 10A. In one embodiment of the cluster tool 10, no cluster tool base10A is used and thus the horizontal motion assembly 90 and processingracks may be positioned on the floor of the region in which the clustertool 10 is installed. In one aspect, the base 464 is positioned abovethe cluster tool base 10A, or floor, by use of the enclosure supports461 to provide an unrestricted and uniform flow path for air to flowthrough the horizontal motion assembly 90. In one aspect the enclosuresupports 461 may also be adapted to act as conventional vibrationdampers. Air flow created by the environmental control assembly 110 orclean room environment that flows through the enclosure 460 in onedirection, preferably downward, will help to reduce the possibility ofparticles generated inside the enclosure 460 from making its way to thesubstrate surface. In one aspect, the slots 471 formed in the enclosuretop plate 462 and the base slots 464A are designed to restrict thevolume of air flowing from the environmental control assembly 110 sothat a pressure drop of at least a 0.1 ″ wg is achieved between theoutside of the enclosure top plate 462 to the interior region of theenclosure 460. In one aspect, a central region 430 of the enclosure 460is formed to isolate this region from the other parts of the horizontalmotion assembly by use of the internal walls 465. The addition ofinternal walls 465 can minimize recirculation of the air entering theenclosure 460 and acts as an air flow directing feature.

Referring to FIG. 12A and FIG. 13A, in one aspect of the enclosure 460,the drive belt is positioned to form a small gap between drive belt 440and the drive belt slot 472 formed in the enclosure top plate 462. Thisconfiguration may be advantageous to prevent particles generated insidethe enclosure 460 from making their way outside of the enclosure 460.

Referring to FIG. 12C, in one another aspect of the enclosure 460, a fanunit 481 may be attached to the base 464 and adapted to draw air frominside the enclosure 460 through the base slots 464A formed in the base464. In another aspect, the fan unit 481 pushes the particulatecontaining air through a filter 482 to remove particles before it isexhausted (see item “A”) through the cluster tool base 10A or floor. Inthis configuration a fan 483, contained in the fan unit, is designed tocreate a negative pressure inside the enclosure 460 so that air outsidethe enclosure is drawn into the enclosure thus limiting the possibilityof particles generated inside the enclosure 460 from leaking out. In oneembodiment, the filter 482 is a HEPA type filter or other type of filterthat can remove the generated particulates from the air. In one aspect,the length and width of the slots 471 and the size of the fan 483 areselected so that a pressure drop created between a point external to theenclosure 460 and a point inside the enclosure 460 is between about 0.02inches of water (˜5 Pa) and about 1 inch of water (˜250 Pa).

In one embodiment of the horizontal motion assembly 90, a shield belt479 is positioned to cover the slots 471 to prevent particles generatedinside of the horizontal motion assembly 90 from making there way to thesubstrate. In this configuration the shield belt 479 forms a continuousloop that runs along the length of the horizontal motion assembly 90 andis positioned in the slot 471 so that the open area formed between theshield belt 479 and the enclosure top plate 462 are as small aspossible. In general, the shield belt 479 is attached to the supportmounts 452 (e.g., bonded, bolted or clamped) to form a continuous loopthat runs along the length of the horizontal motion assembly 90 and issupported at the ends of the horizontal motion assembly 90 by the two ormore drive belt pulleys (not shown). In the configuration illustrated inFIG. 12C, the shield belt 479 may be attached to the support mounts 452at the level of the slot 471 (not shown) and be looped back through thehorizontal motion assembly 90 in a channel 478 machined into the base464 to form a continuous loop. The shield belt(s) 479 thus enclose theinterior region of the horizontal motion assembly 90.

Vertical Motion Assembly

FIGS. 13A-B illustrate one embodiment of the vertical motion assembly95. FIG. 13A is a plan view of the vertical motion assembly 95illustrating the various aspects of the design. The vertical motionassembly 95 generally contains a vertical support 570, vertical actuatorassembly 560, a fan assembly 580, a support plate 321, and a verticalenclosure 590. The vertical support 570 is generally a structural memberthat is bolted, welded, or mounted to the sled mount 451, and is adaptedto support the various components found in the vertical motion assembly95.

The fan assembly 580 generally contains a fan 582 and a tube 581 thatforms a plenum region 584 which is in fluid communication with the fan582. The fan 582 is generally a device that is adapted to impart motionto air by use of some mechanical means, for example, rotating fanblades, moving bellows, moving diaphragms, or moving close tolerancedmechanical gears. The fan 582 is adapted to draw a negative pressure inthe interior region 586 of the enclosure 590 relative to the exterior ofthe enclosure 590 by creating a negative pressure in the plenum region584 which is in fluid communication with the plurality of slots 585formed in the tube 581 and the interior region 586. In one aspect, thenumber, size and distribution of the slots 585, which may be round, ovalor oblong, are designed to evenly draw air from all areas of thevertical motion assembly 95. In one aspect, interior region 586 may alsobe adapted to house the plurality of cables (not shown) that are used totransfer signals between with the various robot hardware assembly 85 andcomponents of vertical motion assembly 95 components with the systemcontroller 101. In one aspect, the fan 582 is adapted to deliver the airremoved from the interior region 586 into the central region 430 of thehorizontal motion assembly 90 where it is then evacuated from thehorizontal motion assembly 90 through the base slots 464A.

The vertical actuator assembly 560 generally contains a vertical motor507 (FIGS. 12A and 13B), a pulley assembly 576 (FIG. 13B), and avertical slide assembly 577. The vertical slide assembly 577 generallycontains a linear rail 574 and a bearing block 573 which are attached tothe vertical support 570 and the motion block 572 of the pulley assembly576. The vertical slide assembly 577 is adapted to guide and providesmooth and precise translation of the robot hardware assembly 85 andalso support the weight an loads created by the movement of the robothardware assembly 85 along the length of the vertical motion assembly95. The linear rail 574 and the bearing block 573 may be linear ballbearing slides, precision shaft guiding systems, or a conventionallinear guide, which are well known in the art. Typical linear ballbearing slides, precision shaft guiding systems, or a conventionallinear guides can be purchased from SKF USA Inc., or the Daedal Divisionof Parker Hannifin Corporation of Irwin, Pa.

Referring to FIGS. 13A and 13B, the pulley assembly 576 generallycontains a drive belt 571, a motion block 572 and two or more pulleys575 (e.g., elements 575A and 575B) which are rotationally attached tothe vertical support 570 and vertical motor 507 so that a support plate(e.g., elements 321A-321B in FIG. 13B), and thus robot hardware assembly85, can be positioned along the length of the vertical motion assembly95. In general, the drive belt 571 is attached to the motion block 572(e.g., bonded, bolted or clamped) to form a continuous loop that runsalong the length of the vertical motion assembly 95 and is supported atthe ends of the vertical motion assembly 95 by the two or more drivebelt pulleys 575 (e.g., elements 575A and 575B). FIG. 13B illustratesone configuration that has two drive belt pulleys 575A-B. In one aspect,the vertical motor 507 is attached to one of the drive belt pulley 575Bso that rotational motion of the pulley 575B will cause the drive belt571 and the support plate(s), and thus robot hardware assembly 85, tomove along the vertical linear slide assemblies 577. In one embodiment,the vertical motor 507 is a direct drive linear brushless servomotor,which is adapted to move the robot hardware assembly 85 relative to thevertical slide assembly 577 and thus the drive belt 571 and two or morepulleys 575 are not required.

The vertical enclosure 590 generally contains a one or more exteriorwalls 591 and an enclosure top 592 (FIG. 9A) and slot 593 (FIGS. 9A, 12Aand 13A). The vertical enclosure 590 is adapted to cover the componentsin the vertical motion assembly 95, for safety and contaminationreduction reasons. In one aspect, the vertical enclosure 590 is attachedand supported by the vertical support 570. Since particles are generatedby mechanical components that roll, slide, or come in contact with eachother, it is important to assure that the components in the verticalmotion assembly 95 do not contaminate the substrate surface while thesubstrates are transferred through the cluster tool 10. The enclosure590 thus forms an enclosed region that minimizes the chance thatparticles generated inside the enclosure 590 will make their way to thesurface of a substrate. Particulate contamination has direct effect ondevice yield and thus CoO of the cluster tool. Therefore, in one aspect,the size of the slot 593 (i.e., length and width) and/or the size of thefan 582 (e.g., flow rate) are configured so that the number of particlesthat can escape from the vertical motion assembly 95 is minimized. Inone aspect, the length (Z-direction) and width (X-direction) of the slot593 and the size of the fan 582 are selected so that a pressure dropcreated between a point external to the exterior walls 591 and theinterior region 586 is between about 0.02 inches of water (˜5 Pa) andabout 1 inch of water (˜250 Pa). In one aspect, the width of the slot593 is between about 0.25 inches and about 6 inches.

The embodiments described herein generally have advantage over the priorart designs that are adapted to lift the robot components by use ofcomponents that must fold, telescope or retract back into itself toreach their lowest position vertical position. The issue arises sincethe lowest position of the robot is limited by the size and orientationof the vertical motion components that must fold, telescope or retractback into itself is due to the interference of the vertical motioncomponents. The position of the prior art vertical motion componentswhen they cannot retract any farther is often called the “dead space,”or “solid height,” due to the fact that the lowest robot position islimited by the height of the retracted components. In general, theembodiments described herein get around this problem since the bottom ofthe one or more transfer robot assemblies 86 are not supportedunderneath by the components in the vertical motion assembly 95 and thusthe lowest position is only limited by the length of the linear rail 574and the size of the robot hardware assembly 85 components. In oneembodiment, as illustrated in FIGS. 13A-13B, the robot assemblies aresupported in a cantilever fashion by the support plate 321 that ismounted to the vertical slide assembly 577. It should be noted that theconfigurations of the support plate 321 and the components in the robothardware assembly 85 as shown in FIGS. 10C-10E are not intended to belimiting to the scope of the invention described herein since theorientation of the support plate 321 and the robot hardware assembly 85may be adjusted to achieve a desired structural stiffness, and/ordesired vertical stroke of the vertical motion assembly 95.

The embodiments of the vertical motion assembly 95 described herein alsohave advantage over the prior art vertical movement designs, such asones that must fold, telescope or retract back into itself, due to theimproved accuracy and/or precision of the robot hardware assembly 85motion due to the constrained motion along a vertical slide assembly577. Thus, in one aspect of the invention, the motion of the robothardware assemblies is always guided by a rigid member (e.g., verticalslide assembly 577) that provides a structural stiffness and positionalaccuracy to the components as they move along the length of the verticalmotion assembly 95.

Dual Horizontal Motion Assembly Configuration

FIG. 14A illustrates one embodiment of a robot assembly 11 that uses atwo horizontal motion assemblies 90 that may be used as one or more ofthe robot assemblies 11A-H shown in FIGS. 1-6 above. In thisconfiguration the robot assembly 11 generally contains a robot hardwareassembly 85, a vertical motion assembly 95 and two horizontal robotassemblies 90 (e.g., elements 90A and 90B). A substrate can thus bepositioned in any desired x, y and z position by the cooperative motionof the robot hardware assemblies 85, vertical robot assemblies 95 andhorizontal robot assemblies 90A-B, from commands sent by the systemcontroller 101. One advantage of this configuration is that thestiffness of the robot assembly 11 structure during dynamic motion ofthe vertical motion assembly 95 along the transfer direction(x-direction) can be enhanced allowing for higher accelerations duringmovement and thus improved substrate transfer times.

In one aspect, the components found in the vertical motion assembly 95,the upper horizontal motion assembly 90B and the lower horizontal motionassembly 90A contain the same basic components discussed above and thuslike numbers will be used where appropriate. In one aspect, verticalmotion assembly 95 is connected to the lower sled mount 451A and uppersled mount 451B which are positioned along the x-direction by use of themotion assembly 442 retained in each of the horizontal motion assemblies90A and 90B. In another embodiment of the robot assembly 11, a singlemotion assembly 442 mounted to one of the horizontal motion assemblies(e.g., element 90A) and the other horizontal motion assemblies (e.g.,element 90B) acts as just a support to guide one end of the verticalmotion assembly 95.

Substrate Grouping

In an effort to be more competitive in the market place and thus reducecost of ownership (CoO), electronic device manufacturers often spend alarge amount of time trying to optimize the process sequence and chamberprocessing time to achieve the greatest substrate throughput possiblegiven the cluster tool architecture limitations and the chamberprocessing times. In process sequences that have short chamberprocessing times and have a large number of processing steps asignificant portion of the time it takes to process a substrate is takenup by the processes of transferring the substrates in a cluster toolbetween the various processing chambers. In one embodiment of thecluster tool 10, the CoO is reduced by grouping substrates together andtransferring and processing the substrates in groups of two or more.This form of parallel processing thus increases the system throughput,and reduces the number of moves a robot has to make to transfer a batchof substrates between the processing chambers, thus reducing wear on therobot and increasing system reliability.

In one embodiment of the cluster tool 10, the front end robot assembly15, the robot assemblies 11 (e.g., elements 11A, 11B, etc. in FIGS. 1-6)and/or the rear robot assembly 40 may be adapted to transfer substratesin groups of two or more to improve the system throughput by parallelprocessing the substrates. For example, in one aspect, the robothardware assembly 85 has multiple independently controllable transferrobot assemblies 86A and 86B (FIG. 10B) that are used to pick up one ormore substrates from a plurality of processing chambers and thentransfer and deposit the substrates in a plurality of subsequentprocessing chambers. In another aspect, each transfer robot assembly 86(e.g., 86A or 86B) is adapted to separately pick-up, transfer and dropoff multiple substrates. In this case, for example, a robot hardwareassembly 85 that has two transfer robot assemblies 86 can be adapted topick-up a substrate “W” using a first blade 87A, from a first processingchamber and then move to second processing chamber to pick-up asubstrate using a second blade 87B, so that they can be transferred anddropped off in a group.

In one embodiment of the robot assembly 11, as illustrated in FIG. 15A,the robot hardware assembly 85 contains two robot hardware assemblies 85(e.g., elements 85A and 85B) that have at least one transfer robotassemblies 86, which are spaced a desired distance, or pitch, apart(element “A”), and are adapted simultaneously to pick-up or drop offsubstrates from two different processing chambers. The spacing, or pitchA, between the two robot hardware assemblies 85 may be configured tocorrespond the spacing between two processing chambers mounted in one ofthe processing racks and thus allow the robot assembly 11 tosimultaneously access the two processing chambers at once. Thisconfiguration thus has particular advantage in improving the substratethroughput and cluster tool reliability by being able to transfer two ormore substrates in groups.

Robot Blade Hardware Configuration

FIGS. 16A-16D illustrate one embodiment of a robot blade assembly 900that may be used with some of the embodiments described herein tosupport and retain a substrate “W” while it is transferred through thecluster tool 10 using a robot assembly 11. In one embodiment, the robotblade assembly 900 may be adapted to replace the blade 87, and thus canbe coupled to the first pulley system 355 or the second pulley system361 components illustrated in FIGS. 10A-10E at the connection point(element “CP”) formed in the blade base 901. The inventive robot bladeassembly 900 is adapted to hold, “grip”, or restrain a substrate “W” sothat the accelerations experienced by a substrate during a transferringprocess will not cause the substrate position to move from a knownposition on the robot blade assembly 900. Movement of the substrateduring the transferring process will generate particles and reduce thesubstrate placement accuracy and repeatability by the robot. In theworst case the accelerations can cause the substrate to be dropped bythe robot blade assembly 900.

The accelerations experienced by the substrate can be broken up intothree components: a horizontal radial acceleration component, ahorizontal axial acceleration component and a vertical accelerationcomponent. The accelerations experienced by the substrate are generatedas the substrate is accelerated or decelerated in the X, Y and Zdirections during the substrate movement through the cluster tool 10.Referring to FIG. 16A, the horizontal radial acceleration component andthe horizontal axial acceleration component are shown as forces F_(A)and F_(R), respectively. The forces experienced are related to the massof the substrate times the acceleration of substrate minus anyfrictional forces created between the substrate and the robot bladeassembly 900 components. In the embodiments described above, the radialacceleration is generally created as the substrate is being rotated intoposition by a transfer robot assembly 86 and can act in either direction(i.e., +Y or −Y directions). The axial acceleration is generally createdas the substrate is positioned in the X-direction by the horizontalmotion assembly 90 and/or by the motion of the transfer robot assembly86 and can act in either direction (i.e., +X or −X directions). Thevertical acceleration is generally created as the substrate ispositioned in the Z-direction by the vertical motion assembly 95 and canact in either direction (i.e., +Z or −Z directions) or cantileverinduced structural vibrations.

FIG. 16A is a schematic plan view of one embodiment of the robot bladeassembly 900 which is adapted to support the substrate “W.” The robotblade assembly 900 generally contains a blade base 901, an actuator 910,a brake mechanism 920, a position sensor 930, a clamp assembly 905, oneor more reaction members 908 (e.g., one shown), and one or moresubstrate support components 909. The clamp assembly 905 generallycontains a clamp plate 906 and one or more contact members 907 (i.e.,two contact members shown in FIG. 16A) mounted on the clamp plate 906.The clamp plate 906, contact members 907, reaction member 908, and bladebase 901 can be made from a metal (e.g., aluminum, nickel coatedaluminum, SST), a ceramic material (e.g., silicon carbide), or a plasticmaterial that will be able to reliably withstand the accelerations(e.g., 10-30 m/s²) experienced by the robot blade assembly 900 duringthe transferring process and will not generate or attract particles dueto the interaction with the substrate. FIG. 16B is side schematiccross-sectional view of the robot blade assembly 900 shown in FIG. 16A,which has been sectioned through the center of the robot blade assembly900. For clarity the components positioned behind the cross-sectionalplane in FIG. 16B have been left out (e.g., contact members 907), whilethe brake assembly 930 has been retained in this view.

Referring to FIGS. 16A and 16B, when in use the substrate “W” is pressedagainst the retaining surface 908B of the reaction member 908 by aholding force (F₁) delivered to substrate “W” by the actuator 910through the contact members 907 in the clamp assembly 905. In oneaspect, the contact members 907 are adapted to contact and urge the edge“E” of the substrate “W” against the retaining surface 908B. In oneaspect, the holding force may be between about 0.01 and about 3kilograms force (kgf). In one embodiment, as shown in FIG. 16A, it isdesirable to distribute the contact members 907 an angular distance “A”apart to provide axial and radial support to the substrate as it istransferred by the robot assembly 11.

The process of restraining the substrate so that it can be reliablytransferred through the cluster tool 10 using the robot blade assembly900 will generally require three steps to complete. It should be notedthat one or more of the steps described below may be completedsimultaneously or sequentially without varying from the basic scope ofthe invention described herein. Before starting the process of pickingup a substrate the clamp assembly 905 is retracted in the +X direction(not shown). The first step starts when a substrate is picked up from asubstrate supporting component (e.g., elements 532A in FIG. 11A-11I,pass-through positions 9A-H in FIGS. 2A, 3A, etc.) so that the substraterests on the substrate supporting surfaces 908A and 909A on the reactionmember 908 and substrate support component 909, respectively. Next, theclamp assembly 905 is then moved in the −X direction until the substrateis restrained on the robot blade assembly 900 by the holding force (F₁)delivered to substrate “W” by the actuator 910 through the contactmembers 907 in the clamp assembly 905 and the reaction member 908. Inthe last step, the clamp assembly 905 is then held, or “locked”, inplace by the brake mechanism 920 to prevent the acceleration of thesubstrate during the transferring process from appreciably varying theholding force (F₁) and thus allow the substrate to move relative to thesupporting surfaces. After the brake mechanism 920 restrains the clampassembly 905 the substrate can then be transferred to another point inthe cluster tool 10. To deposit a substrate to a substrate supportingcomponents the steps described above can be completed in reverse.

In one aspect of the robot blade assembly 900, the brake mechanism 920is adapted to limit the movement of the clamp assembly 905 in at leastone direction (e.g., +X direction) during the transferring process. Theability to limit the motion of the clamp assembly 905 in a directionopposite to the holding force (F₁) supplied by the clamp assembly 905will prevent the horizontal axial acceleration(s) from causing theholding force to appreciably decrease and thus allow the substrate tomove around, which may generate particles, or from being dropped by theblade assembly 900 during the transferring process. In another aspect,the brake mechanism 920 is adapted to limit the movement of the clampassembly 905 in at least two directions (e.g., +X and −X directions). Inthis configuration, the ability to limit the motion of the clampassembly in the directions parallel to the holding force (F₁) directionwill prevent the horizontal axial acceleration(s) from causing theholding force to appreciably increase, which may cause substratebreakage or chipping, or appreciably decrease, which may generateparticles or cause the substrate to be dropped. In yet anotherembodiment, the brake mechanism 905 is adapted to limit all six degreesof freedom of the clamp assembly 905 to prevent, or minimize, themovement of the substrate. The ability to limit the movement of theclamp assembly 905 in a desired direction can be accomplished by usingcomponents that are adapted to restrain the motion of the clamp assembly905. Typical components which may be used to restrain the motion of theclamp assembly 905 may include conventional latching mechanism (e.g.,door latch type mechanisms) or other similar devices. In one aspect, theclamp assembly 905 motion is restrained by of a mechanism that applies arestraining force (element F₂ in FIG. 16A), such as the opposing brakeassembly 920A discussed below.

In one embodiment, a position sensor 930 is used to sense the positionof the clamp plate 906 so that the controller 101 can determine thestatus of the blade assembly 900 at any time during the transferringprocess. In one aspect, the position sensor 930 is adapted to sense thatthere is no substrate positioned on the blade assembly 900, or that thesubstrate has been misplaced on the supporting surfaces (elements 908Aand 909A), by noting that the clamp plate 906 has moved too far in the−X direction due to the position of the clamp plate 906 from a forcedelivered by the actuator 910. Similarly, the position sensor 930 andcontroller 101 may be adapted to sense that a substrate is present bynoting that the clamp plate 906 position is within a range of acceptablepositions corresponding to when a substrate is present. In one aspect,the position sensor 930 is made up of a plurality of optical positionsensors positioned at desired points, a linear variable displacementtransducer (LVDT) or other comparable position sensing device that canbe used to distinguish between acceptable and unacceptable positions ofthe clamp plate 906.

FIG. 16C schematically illustrates plan view of one embodiment of ablade assembly (element 900A) which has an opposing brake assembly 920Athat replaces the schematic representation of the brake mechanism 920 inFIG. 16A. The opposing brake assembly 920A is adapted to restrain theclamp plate 906 in position during a substrate transferring process. Theembodiment illustrated in FIG. 16C is similar to the configurationsillustrated in FIGS. 16A-B except for the addition of the opposing brakeassembly 920A, a actuator assembly 910A and various supportingcomponents and thus, for clarity, like element numbers have been usedwhere appropriate. The embodiment of the robot blade assembly 900Agenerally contains a blade base 901, an actuator assembly 910A, anopposing brake mechanism 920A, a position sensor 930, a clamp assembly905, a reaction member 908, and a substrate support component 909. Inone embodiment, the clamp plate 906 is mounted on a linear slide (notshown) that is attached to the blade base 901 to align and restrain itsmotion of the clamp plate 906 in a desired direction (e.g.,X-direction).

In one embodiment, the actuator assembly 910A contains an actuator 911,an actuator coupling shaft 911A, a coupling member 912, a guide assembly914, a connection member 915, and a connection plate 916 connected tothe coupling member 912 and to clamp plate 906 through the connectionmember 915. The coupling member 912 may be a conventional coupling jointor “floating joint” commonly used to connect various motion controlcomponents together. In one embodiment, the connection plate 916 isdirectly connected to the actuator coupling shaft 911A of the actuator911. The guide assembly 914 may be a convention linear slide assembly,or ball bearing slide, that is connected to the connection plate 916 toalign and guide the motion of the connection plate and thus the clampplate 906. The actuator 911 is adapted to position the clamp plate 906by moving the coupling shaft 911A, coupling member 912, connectionmember 915, and connection plate 916. In one aspect, the actuator 911 isan air cylinder, linear motor or other comparable positioning and forcedelivering device.

In one embodiment, the opposing brake assembly 920A contains an actuator921 which is connected to the blade base 901 and coupled to a brakecontact member 922. In this configuration the opposing brake assembly921A is adapted to “lock”, or restrain, the clamp plate 906 due to arestraining force F₂ generated by the opposing brake assembly 920A. Inone embodiment, the restraining force F₂ is generated by a frictionforce formed between the connection plate 916 and the brake contactmember 922 when the actuator 921 forces (element F₃) the brake contactmember 922 against the connection plate 916. In this configuration theguide assembly 914 is designed to accept a side load generated from thebrake force F₃ delivered by the actuator 921. The generated restrainingforce F₂ that holds the clamp plate 906 in place is equal to the brakeforce F₃ times the static friction coefficient created between the brakecontact member 922 and the connection plate 916. The selection of thesize of the actuator 921, and the brake contact member 922 and theconnection plate 916 materials and surface finish can be optimized toassure that the generated restraining force is always larger than anyforce created during the acceleration of the substrate during thetransferring process. In one aspect, the created restraining force F₂ iswithin a range between about 0.5 and about 3.5 kilograms-force (kgf). Inone aspect, the brake contact member 922 may be made from a rubber orpolymeric type material, such as polyurethane, ethylene-propylene rubber(EPDM), natural rubber, butyl rubber or other suitable polymericmaterials, and the connection plate 916 are made from an aluminum alloyor a stainless steel alloy. In one embodiment, not shown, the couplingshaft 911A of the actuator 911 is directly coupled to the clamp plate906 and the brake contact member 922 of the opposing brake assembly 920Ais adapted to contact the coupling shaft 911A or the clamp plate toprevent their motion.

FIG. 16D schematically illustrates plan view of one embodiment of theblade assembly 900A which has a different configuration of the opposingbrake assembly 920A than what is illustrated in FIG. 16C. In thisconfiguration, the opposing brake assembly 920A contains a lever arm 923that is connected to the brake contact member 922 at one end, theactuator 921 at the other end of the lever arm, and a pivot point “P”that is positioned somewhere between either end of the lever arm. In oneaspect, the pivot point is connected to the blade base 901 and isadapted to support the lever arm 923 and the force F₄ supplied to thelever arm 923 from the actuator 921 as the brake contact member 922 isurged against the connection plate 916. In this configuration, bystrategically positioning the pivot point “P” a mechanical advantage canbe created by use of the lever arm 923 that can be used to supply abrake force F₃, and thus restraining force F₂, that exceeds forcesachieved by direct contact with the force generating component of theactuator 921.

FIG. 16D also illustrates one embodiment of the blade assembly 900A thatcontains compliant member 917 that is positioned between the clamp plate906 and connection member 915 to help sense the presence, ornon-presence, of a substrate on the blade assembly 900A. The complaintmember generally adds an extra degree-of-freedom that is used inconjunction with the position sensor 930 and controller 101 to sensewhether the substrate is present, or not, on the blade assembly 900Aonce the restraining force F₂ has been applied to connection plate 916.If no other degree-of-freedom exists in the blade assembly 900A therestraining force F₂, which prevents, or inhibits, the clamp plate 906from moving, would thus prevent the position sensor 930 and controller101 from detecting the movement or loss of the substrate before orduring the substrate transferring process.

Therefore, in one embodiment, the actuator assembly 910A generallycontains an actuator 911, an actuator coupling shaft 911A, a couplingmember 912, a guide assembly 914, a connection member 915, a compliantmember 917, a clamp plate guide assembly 918, and a connection plate 916connected to the coupling member 912 and to the clamp plate 906 throughthe connection member 915 and complaint member 917. The clamp plateguide assembly 918 is generally a convention linear slide assembly, orball bearing slide, that is connected to the clamp plate 906 to alignand guide its motion.

The complaint member 917 is generally a flexible component, such as aspring, flexure or other similar device that can deliver enough forceupon the release of the potential energy generated by its deflectionduring the application of the holding force F₁ to cause the clamp plate906 to move an amount that can be reliably measured by the positionsensor 930 when the substrate moves or becomes “lost.” In one aspect,the complaint member 917 is a spring that has a spring rate which is lowenough to allow it to reach its “solid height” when the holding force F₁is applied to the substrate. In another aspect, the connection member915, complaint member 917 and clamp plate 906 are designed so that whenthe holding force F₁ is applied, the connection member 915 will comeinto contact with, or “bottom out” on, the clamp plate 906. Oneadvantage of these types of configurations is that they prevent theholding force F₁ from varying during the transferring process, since thecomplaint member 917 is not be able to further deflect due to theaccelerations experienced by the substrate during the transferringprocess, which will reduce the number of generated particles and preventthe loss of the substrate.

The following steps are intended to illustrate an example of how thecomplaint member 917 can be used to sense the presence of the substrateon the blade assembly 900A after the restraining force F₂ is applied tothe connection plate 916. In the first step the actuator 911 applies theholding force F₁ to the substrate through the contact members 907 in theclamp assembly 905 and the reaction member 908 which cause the compliantmember 917 to deflect an amount that causes the gap “G” between theconnection member 915 and the clamp plate 906 to shrink. The controller101 then checks to make sure that the clamp plate 906 is in anacceptable position by monitoring and noting the information receivedfrom the position sensor 930. Once the substrate has been sensed, andthus is in a desirable position on the blade assembly 900A, therestraining force F₂ is applied to the connection plate 916 to limit itsmotion in the direction parallel to the holding force (F₁) direction.Then if the substrate moves, and/or becomes “un-gripped”, the potentialenergy generated in the compliant member 917, due to its deflectionduring the application of the holding force F₁, will cause the clampplate 906 to move away from the restrained connection plate 916 which isthen sensed by the position sensor 930 and controller 101. The notedmovement of the clamp plate 906 by the position sensor 930 will allowthe controller 101 to stop the transferring process or prevent thetransferring process from occurring, which may help prevent damage tothe substrate and system.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method of transferring a substrate, comprising: positioning asubstrate on a substrate supporting device between a substrate contactmember and a reaction member that are positioned on the substratesupporting device; coupling an actuator having a connection member tothe substrate contact member so that the connection member couples theactuator to the substrate contact member; applying a holding force tothe substrate using the actuator that urges the substrate contact memberagainst the substrate and the substrate against the reaction member;storing energy in a compliant member that is positioned between thesubstrate contact member and the connection member; restraining themovement of the connection member after the holding force has beenapplied to minimize the amount of variation in the holding force duringthe process of transferring the substrate; and sensing the movement ofthe substrate by sensing the movement of the substrate contact memberdue to the reduction in the stored energy in the compliant member. 2.The method of claim 1, further comprising halting the movement of thesubstrate supporting device when the sensed movement of the substratecontact member exceeds a user defined value.
 3. The method of claim 1,further comprising transferring a substrate positioned on the substratesupporting device to a first array of processing chambers positionedalong a first direction using a first robot assembly which is adapted toposition the substrate supporting device at a desired position in thefirst direction and at a desired position in a second direction, whereinthe second direction is generally orthogonal to the first direction. 4.The method of claim 3, wherein the second direction is generally alignedin a vertical direction.